Archive for the ‘Tactical Ventilation’ Category

What is Extreme?

There is some debate about the use of the term extreme fire behavior (some of my colleagues indicate that processes such as flashover is not “extreme” but simply “normal” fire behavior). I contend that flashover would potentially be a normal part of fire development, but is also extreme, at least in the context that we are using the word. As defined in the wildland firefighting community:

“Extreme” implies a level of fire behavior characteristics that ordinarily precludes methods of direct control action. One or more of the following is usually involved: high rate of spread, prolific crowning and/or spotting, presence of fire whirls, strong convection column. Predictability is difficult because such fires often exercise some degree of influence on their environment and behave erratically, sometimes dangerously (National Wildfire Coordinating Group Glossary)

In the structural firefighting environment, occurrence of flashover (particularly while firefighters are operating inside the compartment) fits substantially with the description of extreme used by wildland firefighters.

Classification and Understanding

Ontology may be described as definition of a formal representation of concepts and the relationships between those concepts. An ontology provides a shared vocabulary. Unfortunately we do not have a well developed ontology of fire behavior phenomenon and many types of phenomena have more than one definition. As with the use of the word extreme, there is some debate about the need to classify phenomena as being this or that (e.g., flashover or backdraft). I take the position that it is useful (but difficult as we do not have a common classification scheme or ontology). But, I think that it is still worth the effort.

This is a substantive topic for a later post. This post will examine a type of fire gas ignition phenomena that has been involved in a number of incidents in recent years resulting in near misses, injuries, and fatalities.

Fire Gas Ignitions

In a previous post, I posed the question: Backdraft or Smoke Explosion?. This post used a video clip to open a discussion of the difference between these two phenomena. A smoke (or fire gas) explosion is a type of fire gas ignition, but there are a number of other types of fire gas ignition that present a hazard during firefighting operations.

All fire gas ignitions (FGI) involve combustion of accumulated unburned pyrolysis products and flammable products of incomplete combustion existing in or transported into a flammable state (Grimwood, Hartin, McDonough, & Raffel, 2005). In a smoke explosion, ignition of a confined mass of smoke gases and air that fall within the flammable range results in extremely rapid combustion (deflagration), producing an significant overpressure which can result in structural damage. However, what happens if the mass of gas phase fuel is not pre-mixed within its flammable range and does not burn explosively?

The general term Fire Gas Ignition, encompasses a number of phenomena that are related by the common characteristic that they involve rapid combustion of gas phase fuel consisting of pyrolizate and unburned products of incomplete combustion that are in or are transported into a flammable state. For now, let’s differentiate these phenomena from backdraft on the basis of the concentration of gas phase fuel (backdraft involving a higher concentration than fire gas ignition).

Fire gas ignition can involve explosive combustion (as in a smoke explosion) or rapid combustion that does not produce the same type of overpressure as an explosion. One such phenomenon is a flash fire. In this case, gas phase fuel ignites and burns for short duration, but does not release sufficient energy for the fire to transition to a fully developed stage (as occurs in flashover). While a flash fire may not result in flashover, the energy release is still significant and heat flux (energy transferred) can be sufficient result in damage to personal protective equipment, injury and death. This post uses a case study to examine the flash fire phenomenon.

Residential Fire

This case study is based on a near-miss incident involving extreme fire behavior during a residential fire that occurred on October 9, 2007 at 1119 William Street in Omaha, Nebraska. Special thanks to Captain Shane Hunter (Omaha Fire Department Training Officer) for sharing this post incident analysis and lessons learned.

Unlike many of the incidents used as case studies, no one died or was injured during incident operations. In this near miss incident, the firefighters and officers involved escaped without injury, but the outcome could easily have been quite different.

Weather Conditions

Weather was typical for early fall with a light breeze from the south (blowing towards Side C of the fire building).

Building Information

The fire building was a one and a half story, wood frame dwelling with a basement (see Figure 1). The attic space had been renovated into three separate compartments to provide additional living space.

Figure 1. Exterior View Side A

Figure 2. Floor 2 Layout

Conditions on Arrival

When the first company arrived they observed fire and smoke from the second floor window (see Figure 1) and reported a working fire. The doors and windows on the first floor were closed.

Firefighting Operations

What initial actions were taken? A 200′ hoseline was extended through the door located on Side A and through the living room and kitchen to the stairway to the second floor, which was located at the C/D corner of the structure (Figures 2 and 3).

Figure 5 & 6. Kitchen (view from Floor 1) and Stairwell (view from Floor 2)

What did the fire attack crew observe? The living room and kitchen were clear of smoke and the door to the second floor stairway was closed. When this door was opened and the line was advanced up the stairway to the second floor, the company assigned to fire attack encountered smoke down to floor level on the second floor. Making a left turn at the top of the stairs (see Figure 4) the Captain noted high temperature at the floor level and observed rollover at the ceiling level.

• How did the ventilation profile change when the door to second floor stairway was opened? How might this have changed fire behavior?
• What did the depth of the hot gas layer (from ceiling to floor) indicate about the ventilation profile?
• What did rollover in the center compartment indicate?

The Captain instructed the nozzle operator to apply water to the ceiling. The firefighter on the nozzle applied water in a 30^o fog pattern (continuous application). Simultaneously, a crew working on the exterior vented the second floor window on Side C (see Figures 4 and 6).

How did conditions change? The engine company working on floor 2 heard an audible, whoosh as the hot gas layer ignited producing flames down to floor level. Operation of the hoseline (30^o fog pattern) had no immediate effect. The Captain ordered the crew to retreat into the stairwell and continue water application.

• What extreme fire behavior phenomena occurred?
• What were the initiating events that caused this rapid fire progression?

Figure 4. Floor 2 Side A (Looking Towards Side A)

Figure 5. Floor 2 Side C (Looking Towards Side C)

What action was taken? While the engine company operated from the stairwell, vertical ventilation was completed over the center compartment (see Figures 4 and 5). After the creation of an exhaust opening in the roof, conditions on floor 2 became tenable and the engine crew was able to knock the fire down within several minutes.

• Why did conditions improve quickly after the creation of a vertical exhaust opening?
• What tactical options might have prevented this near miss?

Observations and Analysis

Captain Shane Hunter observed that the initial fire attack crew viewed this incident as an easy job. They thought that an attack from the unburned side would simply push the fire out the window where fire was initially showing on Side A. Why did things turn out so differently than anticipated?

In his analysis of this incident, Captain Hunter points out that there is a considerable difference between a “self-vented” fire and an adequately ventilated fire. As discussed in the April 2008 Officer’s Corner (GFES), horizontally ventilated fires are likely to remain ventilation-controlled. It is important to read the Building, Smoke, Air Track, Heat, and Flame (B-SAHF) indicators to determine the current burning regime (fuel or ventilation-controlled) and anticipate the effect of changes to the ventilation profile.

The fire in the compartment of origin reached flashover resulting in the extension of flames into the center compartment as evidenced by the observation of rollover by the Captain of the engine company performing fire attack. However, the center compartment and the compartment on Side C did not experience flashover (note the condition of contents in the center compartment in Figure 6.). If flashover did not occur in these two compartments, what happened?

In this incident, the fire gases ignited in a flash fire, but combustion did not rapidly transition to a fully developed state in the two compartments adjacent to the compartment of origin.

A flash fire rapidly increases heat release rate, temperature within the compartment and heat flux (as experienced by the fire attack crew in this incident). Like rollover, this phenomenon should not be confused with flashover as fuel in the lower region of the compartment may or may not ignite and sustain combustion. However, fire gas ignition can precede and precipitate flashover (should the fire quickly transition to the fully developed stage).

The concentration of fuel within the hot gas layer varies considerably, with higher concentrations at the ceiling. Concentrations within the flammable range most commonly develop at the interface between the hot gas layer and the cooler air below. Isolated flames (an indicator of a ventilation-controlled fire) are most commonly seen in the lower region of the hot gas layer (as there may be insufficient oxygen concentration in the upper level of the hot gas layer to support flaming combustion). Mixing of the hot gas layer and air due to turbulence increases the likelihood of a significant fire gas ignition.

• What was the ventilation profile and air track when the engine company reached the top of the stairs to begin their attack on the fire?
• How did the tactical ventilation performed from the exterior (removal of the window on floor 2, Side C) influence the ventilation profile and air track?
• What effect do you think that continuous operation of the 30^o fog stream had on conditions on floor 2?
• What combination of factors likely resulting in mixing of air and smoke (fuel) leading to the fire gas ignition that drove the fire attack crew off floor 2 and into the stairwell?

Key Considerations and Lessons Learned

This incident points to a number of key considerations and lessons learned.

• Beware the routine incident! Even what appears to be a simple fire in a small residential structure can present significant challenges and threats to your safety.
• Use the B-SAHF indicators to read the fire and consider both the stage of fire development and burning regime (fuel or ventilation-controlled) in strategic and tactical decision making.
• Flame showing is just that. Do not be lulled into a false sense of security by thinking that the fire is adequately ventilated. Read the air track indicators!
• Continue to read the fire after making entry. Smoke is fuel and hot gases overhead are a threat. Observation of isolated flames indicates a ventilation-controlled fire. Rollover often precedes flashover. Take proactive steps to mitigate the threat of extreme fire behavior.
• Recognize that ventilation-controlled fires will increase in heat release rate if additional air is introduced. Manage the ventilation profile using tactical ventilation and tactical anti-ventilation. Anticipate unplanned ventilation due to fire effects.
• Recognize that both horizontal and vertical ventilation are effective when used appropriately and coordinated with fire control. Consider the influence of inlet and exhaust opening location and size when anticipating the influence of tactical ventilation on fire behavior and conditions within the building.

Again special thanks to Captain Shane Hunter and the Omaha Fire Department for sharing the information about this incident and their work to improve firefighter safety.

Ed Hartin, MS, EFO, MIFireE, CFO

When fire is showing from one or more windows or other opening on arrival, firefighters and fire officers often observe that the fire is �self-vented�. While this is true, this unplanned ventilation often increases heat release rate and does not have the desirable effects resulting from effective tactical ventilation.

Effects of Horizontal Ventilation

Effect of Positive Pressure ventilation on a Room Fire (Kerber & Walton, 2005) describes a series of experiments performed at the National Institute of Standards and Technology (NIST) to determine the effect of horizontal ventilation using a window and door under natural and positive pressure conditions. These experiments involved a compartment with a single window and doorway as illustrated in Figure 1. The room was furnished as a bedroom with a limited fuel load consisting of a bunk bed, bookcase (without books), chair, and desk with computer monitor.

Figure 1. Horizontal Ventilation Test Floor Plan

As illustrated in Figure 2, with natural ventilation the heat release rate (HRR) spiked immediately after the window was vented. As heat release rapidly increased, so too did temperature with peak temperature at the ceiling in excess of 1000^o C (1832^o F).

Figure 2. Heat Release Rate with Natural Horizontal Ventilation

Note: Adapted from Effect of positive pressure ventilation on a room fire, (NISTIR 7213) by S. Kerber & W. Walton

After establishing natural horizontal ventilation by opening the window, a bi-directional air track developed at both the window and door to the compartment as illustrated in Figures 3 and 4. If this compartment was at the end of �a long hallway, what impact would the air track and temperature conditions have on firefighters working their way to the seat of the fire?

Figure 3. Air Track at the Door

Figure 4. Air Track at the Window

Click on the link to view video providing interior and exterior views: NIST Natural Horizontal Ventilation Test . Additional information on natural and positive pressure ventilation tests is also available on the NIST PPV web page.

Horizontal ventilation is often performed to lower temperature and raise the level of the hot gas layer in the fire area. While increased ventilation may accomplish this, failure (or tactical ventilation) of a single window is unlikely to have significant impact on compartment temperature.

Researchers from the University of Texas and the Austin Texas Fire Department (Weinschenk., Ofodike,& Nicks, 2008) performed a computer simulation of the impact of variation in the size of the exhaust opening when performing horizontal ventilation using a window and door. The compartment size was slightly smaller than in the NIST study (Kerber & Walton, 2005) and the fire was considerably smaller (2 MW). In this simulation they examined conditions varying from the window being closed to fully open. As illustrated in Figure 5, even with the window fully open, the temperature in the doorway of the compartment dropped only slightly.

Figure 5. Influence of Opening Size on Doorway Temperature

It is essential to recognize that unplanned ventilation caused by failure of window glazing due to the effects of the fire are unlikely to result in sufficient exhaust opening size to have a significant positive influence on conditions inside the fire compartment and adjacent spaces.

What smoke, flame, and air track indicators would point to ventilation controlled conditions? Take a look at Figures 3 and 4! How might tactical anti-ventilation and/or tactical ventilation be used to positively influence fire conditions and the environment in the compartment?

So What?

Horizontal ventilation is an excellent tool when used correctly. However, not understanding the influence of changes to the ventilation profile when the fire is ventilation controlled, can have disastrous consequences. Ventilation direction (horizontal or vertical), size and location of inlet and exhaust openings, and coordination with fire control are critical to safe and effective fireground operations.

References

For more information, see the following NIST report and journal article.

Kerber, S. & Walton, W. (2005). Effect of positive pressure ventilation on a room fire, (NISTIR 7213). Retrieved January 26, 2009 from http://fire.nist.gov/bfrlpubs/fire05/PDF/f05018.pdf

Weinschenk, C., Ofodike, E., & Nicks, R. (2008) Analysis of fireground standard operating guidelines/procedures for compliance for Austin fire department. Fire Technology, 44(1), 39-64.

Remember the Past

I am involved in an ongoing project to assemble and examine narratives, incident reports, and investigations related to extreme fire behavior events. Unfortunately many of these documents relate to line of duty deaths. As I read through the narratives included in the United States Fire Administration line of duty death database and annual reports on firefighter fatalities, I realized that every week represents the anniversary of the death of one or more firefighters as a result of extreme fire behavior.

While some firefighters have heard about the incidents involving multiple fatalities, others have not and most do not know the stories of firefighters who died alone. In an effort to encourage us to remember the lessons of the past and continue our study of fire behavior, I will occasionally be including brief narratives and links to NIOSH Death in the Line of Duty reports and other documentation in my posts.

January 28, 1994
Firefighter Vencent Acey, 42, Career
Firefighter John Redmond, 41, Career
Philadelphia Fire Department, Pennsylvania

On January 28, Firefighters Vencent Acey and John Redmond, both of the Philadelphia (PA) Fire Department, died when he became trapped and overcome by smoke by a rapidly moving fire in the basement of a church. Several firefighters re-entered the church against orders to rescue the firefighters, and were able to pull one of them from the basement. Eight other firefighters were injured, including several involved in the rescue efforts.

January 28, 1995
Firefighter Victor Melendy, 47, Career
Stoughton Fire Department, Massachusetts

On January 28, Firefighter Victor Melendy of the Stoughton (MA) Fire Department died when he was caught in a flashover while searching for victims on the third floor of a rooming house.

January 27, 2000
Captain Walter Harvey Gass, 74, Volunteer
Sealy Volunteer Fire Department, Texas

Captain Gass and other members of his department were dispatched to a residential structure fire that was caused when lightning struck a house. The first two firefighters on the scene, the Assistant Chief and the Fire Chief, confirmed a working fire with dark smoke and fire visible from the attic and dormers. Captain Gass and his crew were the first fire company to arrive at the scene. Captain Gass and two firefighters entered the structure through the front door to perform an aggressive attack on the fire. Shortly after entering the structure, the two firefighters who were with Captain Gass were attempting to feed more hose into the structure. There was a rapid buildup of heat and the hoseline seemed to drop. The firefighters exited the building and reported this situation to the Chief. Two Rapid Intervention Teams (RIT) were formed and, after four attempts, the second team was successful in recovering Captain Gass. Captain Gass was equipped with full structural protective clothing and a manually activated PASS device. The PASS was found in the “off” position. Captain Gass was located about 18 feet inside the front door of the structure. Captain Gass was removed from the structure approximately 20 minutes after his arrival on the scene. The cause of death was listed as smoke and soot inhalation with greater than 80 percent total thermal injury. Additional information about this incident may be found in NIOSH Fire Fighter Fatality Investigation F2000-09.

Seeking Information

If your department experiences (or has experienced) an extreme fire behavior event and you would be willing to share information about the incident or lessons learned, please contact me by e-mail or telephone.

Warning! Science Ahead

This post attempts to bring some clarity to a few scientific concepts that are often overlooked or oversimplified in fire behavior training for firefighters and fire officers. I have made an effort to make this information accessible, but not to reduce it to the point where it no longer makes sense from a scientific perspective.

Fire Power

In physics, power is the rate at which work is performed or energy expended for a given unit of time. For combustion, power is the energy released per unit of time or heat release rate (HRR). So what? Why is this important to firefighters?

It is relatively easy to describe how big a compartment or building is based on its dimensions (i.e., length, width, height) in meters (or feet). However, describing how big a fire is requires different units of measure. Likely the best way to describe the size� of a fire is on the basis of the rate at which it is releasing energy.

In Heat Release Rate: A Brief Primer, Dr. Vytenis Babrauskas observes that Heat Release Rate (HRR) is the driving force that influences many other dimensions of the fire environment. As HRR increases, temperature and the rate of temperature change both increase, accelerating fire development. In addition, increased HRR results in reduced oxygen concentration and increased production of gaseous and particulate products of incomplete combustion. For firefighters, it is also important that HRR directly relates to flow rate required for fire control.

Measuring Energy and Power

Energy is often defined as the ability to do work or cause change. Thermodynamic work is the transfer of energy from one system to another. This is sometimes, but not always accompanied by an increase in temperature (more on this in a bit).

In the United States, the traditional units of measure for energy were the British thermal unit (Btu). A Btu is the amount of energy required to raise the temperature of one pound of water from 60^o F to 61^o F. Adding additional Btu will continue to raise the temperature of the water until it reaches its boiling point. Changing phase from liquid to gas requires input of a large amount of energy, but there is no change in temperature!

The standard international (SI) unit for energy is the Joule (J). The joule is defined in terms of mechanical energy. However, in our context, it is useful to describe the Joule in terms of transfer of thermal energy. 4186 J will raise the temperature of 1 kilogram (kg) of water from 20^o C to 21^o C. For readers who are more comfortable with Btu, one Btu is equal to 1055 J (slightly more than one kilojoule (kJ)).

Power is the rate at which work is performed or energy is transferred. This necessitates a measure of the amount of energy (i.e., Btu or J) and a unit of time (generally minutes or seconds). Using traditional units, power could be described in terms of Btu/minute or Btu/second. Watts are the SI unit for power, with a Watt being a Joule/second (J/s)

To keep things simple, the remainder of this post will stick to the SI units (Joules, Watts, and ^oC).

Potential Energy of Fuel

Energy that is stored is known as potential energy. Fuel has chemical potential energy that is released as the fuel is oxidized in the combustion process. The energy that is released through complete combustion of a given mass of fuel is known as the heat of combustion. Heat of combustion is dependent on the chemical makeup of the fuel. Heat of combustion is usually expressed in kilojoules/gram (kJ/g) or megajoules/kilogram (MJ/kg).

Generally (hydrocarbon based) synthetic fuels have a higher heat of combustion than cellulose fuels such as wood as illustrated in the following table:

Note: Data in this table is from the Society of Fire Protection Engineering (SFPE) Handbook of Fire Protection Engineering.

When fuel burns, the total energy that can be released is dependent on its heat of combustion and fuel mass (e.g., kg of fuel)

Heat of combustion is important, but as Dr. Babrauskas points out, the rate at which that energy is released is even more important. Heat release rate is influenced by a number of different fuel characteristics such as surface area to mass ratio, orientation (e.g., horizontal, vertical), arrangement, and geometry.

The concepts of heat of combustion and heat release rate help explain changes in the built environment that impact firefighting. Increased use of synthetic materials has increased the chemical potential energy of building materials and contents and higher heat release rates shorten time to flashover.

Oxygen and Combustion

Release of chemical potential energy from fuel depends on availability of adequate oxygen for the combustion reaction to occur. Interestingly, while the heat of combustion of various types of organic (carbon based) fuel varies widely, the amount of oxygen required for release of a given amount of energy remains remarkably consistent.

In 1917, British scientist W.M. Thornton discovered that the amount of oxygen required per unit of energy released from many common hydrocarbons and hydrocarbon derivatives is fairly constant. In the 1970’s, researchers at the National Bureau of Standards independently discovered the same thing and extended this work to include many other types of organic materials and examined both complete and incomplete combustion.

Each kilogram of oxygen used in the combustion of common organic materials results in release of 13.1 MJ of energy. This is referred to as Thornton’s Rule.

However, the concentration of oxygen in the atmosphere is only 21%. Examining the relationship between consumption of atmospheric oxygen and energy release requires adaptation of Thornton’s Rule based on oxygen concentration. Multiplying 13.1 MJ/kg of oxygen by 21% gives a value of 2.751 MJ/kg of air. The Society of Fire Protection Engineering (SFPE) Handbook of Fire Protection Engineering rounds this value to 3.0 MJ/kg of air. While it is easy to understand that air has mass, it is a bit more difficult to visualize a kilo of air! The density of dry air at sea level and at a temperature of 20o C is 1.2 kg/m³ (0.075 lbs./ft³). Air density decreases as temperature or moisture content of the air increases, but this provides a starting point for visualizing the relationship between volume and mass at normal temperature and pressure.

All this is very interesting, but how does it relate to compartment fires and firefighting?

Fuel and Ventilation

In a compartment fire, combustion occurs in an enclosure where the air available for combustion is limited by 1) the volume of the compartment and 2) ventilation.

Consider a 2.4 m x 3.7 m (8′ x 12′) compartment with a ceiling height of 2.4 m (8′). A compartment of this size has a volume of 21.312 m³ (752.63 ft³). Based on a potential heat release of 3 MJ/m³ of air, the volume of the compartment would provide sufficient air for release of 63.936 MJ. A fire burning in this compartment with a steady heat release rate of .5 MW would consume the air in the compartment in just over two minutes (127.8 seconds). However, this is an extreme oversimplification as fires generally begin with a low heat release rate and grow until they become limited by the availability of fuel or oxygen. In this case, the fire would burn for a bit longer and would then cease flaming combustion, but surface combustion may (depending on the type of fuel involved) continue for some time after the oxygen concentration drops below 15%.

It is unlikely that a fire would occur in a compartment that had no openings (or at least potential openings) such as a door and one or more windows. Even if these openings are closed, there will likely be some leakage that will influence the amount of air available to support combustion. If they are open, a substantially greater amount of air will be available to support fire growth. However, as the fire develops and a hot gas layer forms and begins to fill the compartment, exiting smoke reduces the size of the opening serving as an inlet for additional air. As this occurs, the fire becomes ventilation controlled and heat release is limited by the amount of oxygen in the air available to support combustion.

Note: Photos adapted from National Institute of Standards and Technology (NIST) ISO-Room/Living Room Flashover.

Hazard of Ventilation Controlled Fires

Many if not most fires that have progressed beyond the incipient stage when the fire department arrives are ventilation controlled. This means that the heat release rate (the fires power) is limited by the ventilation profile, in particular, the existing openings.

If ventilation is increased, either through tactical action or unplanned ventilation resulting from effects of the fire (e.g., failure of a window) or human action (e.g., exiting civilians leaving a door open), heat release rate will increase.

Ventilation is a complex strategy as it can have both positive and negative effects. Releasing smoke can make the interior environment more tenable by raising the level of the hot gas layer and removing energy and fuel (hot smoke) from the compartment or building. However, increasing the air supply to a ventilation controlled fire will increase the heat release rate, potentially resulting in a ventilation induced flashover.

It is essential that firefighters and fire officers understand the effects of tactical operations on fire behavior and coordinate their efforts to maximize the positive impact while limiting the negative consequences.

Chief Pete Lamb recently wrote a blog post titled Vent Early in which he emphasizes the need for firefighters to understand the application of ventilation strategies and to use them effectively. I suggest that we vent wisely in coordination with fire attack after considering fire behavior and building factors! Understanding compartment fire behavior and practical fire dynamics is critical to safe and effective ventilation operations.

If you found this post interesting or useful (or not), please leave a comment with your feedback.

Ed Hartin, MS, EFO, MIFireE, CFO

Applying NIOSH Recommendations

NIOSH Death in the Line of Duty reports generally contain two types of recommendations, those that focus on specific contributory factors and others that address general good practice. As when examining contributory factors, it is important to read the NIOSH recommendations critically. Do you agree or disagree and why? What would you change and what additional recommendations would you make based on the information presented in the report?

Brief Review of the Incident

NIOSH Report F2008-06 examines a fire in a wood frame duplex that resulted in injury to Lieutenant Scott King and the death of Firefighter Brad Holmes of the Pine Township Engine Company. The fire occurred on February 29, 2008 in Grove City, Pennsylvania.

When the fire department arrived, the unit on Side D was substantially involved and a female occupant was reported trapped in the building. Initial operations focused on fire control and primary search of Exposure B. Rapid fire development trapped Lieutenant King and Firefighter Holmes while they were searching Floor 2 of Exposure B.

The following photographs are part of a series of 37 pictures taken during this incident and provided to NIOSH investigators during their investigation.

Additional detail on this incident is provided in Developing & Using Case Studies: Pennsylvania Duplex Fire Line of Duty Death (LODD) and Pennsylvania Duplex Fire: Firefighting & Firefighter Rescue Operations . In addition, readers should review NIOSH Report F2008-06.

Recommendations

NIOSH Report F2008-06 contains 11 recommendations. Several of these recommendations are well grounded in the contributory factors identified in the report. Others have a more indirect relationship to the factors influencing the injury to Lieutenant King and death of Firefighter Holmes.

Recommendation #1: Fire departments should be prepared to use alternative water supplies during cold temperatures in areas where hydrants are prone to freezing.

In preparation for potential issues, fire departments should develop standard operating procedures (SOPs) for temporary water sources to be dispatched like tankers, water shuttles, or portable drop tanks.

While this recommendation is valid and good practice, it has little to do with loss of water as a contributory and likely causal factor in the injury to Lieutenant King and death of Firefighter Holmes. Had Command been notified immediately of the frozen hydrant and implemented alternate water supply strategies, the outcome would have likely been the same if tank water had been used as it was in this incident to sustain initial operations.

However, it is critical for fire departments to have a plan to respond to respond to water supply problems. In this case, apparatus had substantial tank water which was used to support initial firefighting operations. In addition, there was sufficient hose available on first alarm companies to stretch to other hydrants (such as the one eventually used east of Garden Avenue on Craig Street). Use of a reverse lay to establish water supply allows the apparatus operator to continue the lay to the next hydrant (hose capacity permitting) or another apparatus to continue the lay and establish a relay. Depending on the distance to the next operational water source, this could be considerably more efficient and rapid than waiting for greater alarm resources to establish a tender shuttle.

Recommendation #2: Fire departments should ensure that search and rescue crews advance or are protected with a charged hoseline.

This recommendation is critical. However, the discussion fails to speak to the need for backup lines to protect the means of egress when crews are working above the fire. Recent incidents in Loudoun County, Virginia and Sacramento California, resulted in crews with a hoseline working above the fire without a backup line having their hose burn through, and means of egress cut off, necessitating emergency egress via second floor windows.

Recommendation #3: Fire departments should ensure fire fighters are trained in the tactics of a defensive search.

While training in search under marginal circumstances is important, this recommendation fails to speak to the need to understand fire behavior and applied fire dynamics as a foundation for maintaining situational awareness on the fireground. This applies to command personnel, company officers, and individual firefighters. While there are a number of points in the sequence of events that lead to Lieutenant King’s injury and Firefighter Holmes’s death, all are dependent on this. Failure to recognize the potential for extension and rapid fire progress, the influence of creating ventilation openings on Floor 2, and recognition of developing fire conditions were likely the most significant causal factor in this incident. Had this not been the case, the firefighters and officers involved would have had the opportunity to adjust their tactical operations or exit the building prior to the occurrence of the extreme fire behavior that trapped the search team.

NIOSH Report F2008-06 quotes Deputy Chief Vincent Dunn regarding flashover indicators:

There are two warning signs that may precede flashover: heat mixed with smoke and rollover. When heat mixes with smoke, it forces a fire fighter to crouch down on his hands and knees… As mentioned above, rollover presages flashover.

This statement is scientifically incorrect. Heat is simply energy in transit due to temperature difference. It is not a substance and cannot mix with anything else. Increasing temperature is an indicator of potential for flashover, but perception of a rapid increase in temperature is not certain to give adequate warning to take corrective action or escape from the hazardous situation. In addition, rollover does not always precede flashover (it is an important indicator, but only one of many).

The report also quotes Chief Dunn regarding defensive search tactics.

Three defensive search tactics are as follows:

1. At a door to a burning room that may flashover, fire fighters should check behind the door to the room and sweep the floor near the doorway. Fire fighters should not enter the room until a hose line is in position.
2. When there is a danger of flashover, fire fighters should not go beyond the “point of no return.” The point of no return is the maximum distance that a fully equipped fire fighter can crawl inside a superheated, smoke-filled room and still escape alive if a flashover occurs. The point of no return is approximately five feet inside a doorway or window.
3. When searching from a ladder tip placed at a window, look for signs of rollover if one of the panes has been broken. If rollover is present, do not go through the window. Instead, crouch below the heat and sweep the interior area below the windowsill with a tool. If a victim has collapsed there, you may be able to crouch below the heat enough to pull him to safety.

While these tactics have validity, making for search without without protection of a hoseline even to Chief Dunn’s “point of no return”� presents a significant risk. Further, I am uncertain that there is any scientific evidence supporting the concept of the point of no return as described by Chief Dunn. There are numerous examples of situations where firefighters thought they had time to complete a search, but were trapped by extremely rapid fire development. The risk of searching under marginal conditions requires firefighters to effectively read the fire and mitigate hazards in the fire environment through effective use of gas cooling and control of the ventilation profile (either tactical ventilation or anti-ventilation as appropriate) and establishing fire control in addition to primary search.

Recommendation #4: Fire departments should ensure that fire fighters conducting an interior search have a thermal imaging camera.

The thermal imaging camera is a tremendous technological innovation which can significantly speed search operations and provide visual indication of differences in thermal conditions. However, implementation of this recommendation would not necessarily have impacted on the outcome of this incident.

Recommendation #5: Fire departments should ensure ventilation is coordinated with interior fireground operations.

In the discussion of this recommendation, the NIOSH Report F2008-6 states “By eliminating smoke, heat, and gases from the fire it will help minimize flashover conditions”�

This statement is not always true. The influence of ventilation on fire development is dependent on burning regime (fuel or ventilation controlled) and the location of the inlet and exhaust openings. Heat release rate from a ventilation controlled fire will increase as ventilation is increased, potentially taking the fire to flashover (rather than the reverse as indicated by the statement in this NIOSH report). In addition, creation of an air track that channels the spread of hot gases and flames to additional fuel packages can result in fire extension and subsequent flashover. Both of these factors were likely to have been significant in this incident. Coordination of ventilation and search or ventilation and fire attack (as frequently stated in NIOSH reports related to incidents involving extreme fire behavior) requires knowledge of fire dynamics and the influence of ventilation in fire behavior.

Recommendation #6: Fire departments should ensure that Mayday protocols are developed and followed.

This recommendation is important, but fails to address other individual level survival skills that must be integrated with these procedures. For example, in this incident, the Lieutenant and Firefighter might have been able to take refuge in one of the bedrooms, closing the door to provide a barrier to hot gases and flames. A ladder was initially placed to a window in the bedroom on Side B (in close proximity to the location where Firefighter Holmes was found). Ladders were subsequently placed to the bedroom windows on Side A. While it may have been difficult to accomplish this under conditions of extreme thermal insult, if developing conditions had been recognized soon enough (see my earlier observation on situational awareness), this may have bought critical seconds and allowed the trapped search team to escape or be rescued.

Recommendation #7: Fire departments should ensure that the Incident Commander receives pertinent information during the size-up (i.e., type of structure, number of occupants in the structure, etc.) from occupants on scene and that information is relayed to crews upon arrival.

Had the Incident Commander received more specific information from the occupants or law enforcement, this may have shifted focus in search operations as survivability in the original fire unit was doubtful. Despite this, the civilian casualty was later located outside the fire unit, behind the door in the front foyer that served both dwelling units.

Recommendation #8: Fire departments should ensure that fire fighters communicate interior conditions and progress reports to the Incident Commander.

This is a key element in maintaining situational awareness (on the part of the Incident Commander). However, it is equally important for Command to communicate with interior crews regarding conditions observed from the exterior or situations (such as water supply limitations) that will impact interior operations.

Recommendation #9: Fire departments should develop, implement, and enforce written standard operating procedures (SOPs) for fireground operations.

This recommendation focuses on general good practice, but is not tied to specific contributing factors related to the injuries and fatality that resulted in this incident. This type of recommendation should likely be included, but placed in a separate section so as not to dilute the focus on lessons learned.

Recommendation #10: Fire departments and municipalities should ensure that local citizens are provided with information on fire prevention and the need to report emergency situations as soon as possible to the proper authorities.

Recommendation #11: Building owners and occupants should install smoke detectors and ensure that they are operating properly.

If implemented prior to this incident, Recommendations #10 and #11 would likely have had a positive impact on its outcome, particularly with regards to the civilian casualty and the severity of conditions encountered by the firefighters.

However, these two recommendations do not go far enough. Citizens must also recognize the need for rapid egress and the value of closing doors to confine the fire and limit inlet of air required for continued fire development and increasing heat release rate.

Detailed Case Study

CFBT-US has developed a detailed case study based on this incident and the data contained in NIOSH Report F2008-06. Download the Grove City, Pennsylvania Residential (Duplex) Fire Case Study in PDF format.

Now What?

Over the last two weeks we have spent considerable time with a NIOSH Report F2008-06. NIOSH has completed 335 investigations during the first 8 years that this program has been in existence. 49 more investigations are pending. The information contained in these reports provides a vast reservoir of data that can be used to deepen understanding of your craft and improve decision-making and risk management skills.

Make a commitment to developing your expertise as a firefighter or fire officer in the new year and for the rest of your life. Look for the this logo (more information to follow)!

Have a safe and happy new year!

Ed Hartin, MS, EFO, MIFIreE, CFO

I would like to extend my thanks to Steve Berardinelli and Tim Merinar of the NIOSH Firefighter Fatality Investigation and Prevention Program for their assistance in developing the Case Study based on NIOSH Report F2008-06. Just prior to my first post regarding this incident, I forwarded a request for additional information to the NIOSH staff and received a quick response from Tim that he would forward my request to the investigators. This morning I had an excellent conversation with Steve and obtained additional information that was extremely helpful in refining the case.

I will be revising Developing & Using Case Studies: Pennsylvania Duplex Fire Line of Duty Death (LODD) and Pennsylvania Duplex Fire: Firefighting & Firefighter Rescue Operations based on additional information provided by NIOSH. Changes include addition of information related to the ventilation profile, initial fire conditions, and occupant actions.

Analysis and Critique

It is important to note that the observations in this post regarding the contributory factors identified in NIOSH Report F2008-06 are made as a critical friend. Most firefighters and fire officers who read this (or any) NIOSH report will agree with some of the recommendations, may disagree with others, and undoubtedly would make additional recommendations based on their individual assessment of the incident. Analysis of contributing factors and recommendations (rather than simply accepting them) is an important element in the learning process. Dig a bit deeper and build an understanding of why events may have unfolded the way that they did. Identify the critical points at which the outcome could have been changed (there are likely more than one). Think about how these recommendations might apply to you and your department.

As discussed in my earlier post; Criticism Versus Critical Thinking, the intent of this analysis and critique is to share what I have learned from this case, with all due respect to those involved. The firefighters and fire officers involved in this incident were faced with a difficult situation to begin with, having an occupant reported trapped in the building. This was compounded by challenging water supply problems due to multiple frozen hydrants. It is far easier to examine incident information in a comfortable environment with no time pressure than to deal with these issues in the cold, early morning hours.

My original intent was to examine both the contributory factors and recommendations in NIOSH Report F2008-06. However, due to length, this critique will be divided into two separate posts.

A Brief Review of the Incident

On February 29, 2008 The Grove City Fire Department, Pine Township Engine Company, and East End Fire Department responded to a fire in a two-story, wood frame duplex in Grove City, Pennsylvania. Initial dispatch information and the initial size-up indicated that a female occupant was trapped in the building. When the Chief and first engine company arrived, the unit on Side D was substantially involved with smoke in the unit on Side B. Several hoselines were placed into operation for fire control, but fire conditions precluded an offensive attack in the involved unit. Pine Township Engine 85 was assigned to search and rescue of the trapped occupant. Firefighter Brad Holmes and Lieutenant Scott King were tasked with primary search of Exposure Delta. Firefighting operations were hampered by two frozen hydrants, necessitating support of initial operations using only apparatus tank water while an operable hydrant was located. During their search, water supply was interrupted and rapidly deteriorating conditions trapped the search crew. After being rescued by the Rapid Intervention Team, both members were transported to Pittsburgh’s Mercy Hospital Burn Unit. Firefighter Brad Holmes had burns over 75% of his body, and died from his injuries on March 5, 2008. Lieutenant King suffered less serious injuries and was treated and released. A 44 year old female occupant of the dwelling also died.

Figure 1. 132 Garden Avenue-Side Alpha

Note: Fire Department Photo – NIOSH Death in the Line of Duty Report F2008-06. This photo likely illustrates conditions after 0635 (approximately 19 minutes after arrival of the first fire unit, Chief 95).

Additional detail is provided in Developing & Using Case Studies: Pennsylvania Duplex Fire Line of Duty Death (LODD) and Pennsylvania Duplex Fire: Firefighting & Firefighter Rescue Operations. In addition, readers should review NIOSH Report F2008-06.

Contributory Factors

NIOSH Report F2008-06 identifies seven contributory factors in the injury of Lieutenant King and death of Firefighter Holmes. While each of these factors may have had some influence on the outcome of this incident, this analysis provides insufficient clarity and misses several key factors.

• Inadequate water supply. Two hydrants in the vicinity of the burning structure were frozen from the cold weather.
• The victim and injured Lieutenant did not have the protection of a charged hoseline during their search for the trapped occupant.
• Inadequate training in defensive search tactics.
• Non-use of a thermal imaging camera which may have allowed the search and rescue crew to advance more quickly through the structure.
• Ventilation was not coordinated with the interior search.
• Size-up information about the structure was not relayed to the interior search crew. The interior crew was searching in the wrong duplex for the trapped occupant and did not realize they were in a duplex.
• The incident commander was unaware of the search crew’s location in the building. He did not receive any interior reports and was concentrating on resolving water supply issues.

Water Supply: The lack of a continuous water supply likely influenced the loss of the structure and loss of water supply to handlines was in all probability a causal factor in the injury of Lieutenant King and death of Firefighter Holmes. However, the volume of tank water available on apparatus that arrived prior to the search team becoming trapped on Floor 2 (5000 gallons) was likely adequate to support search of the uninvolved areas of the building and confine the fire to the unit of origin for the time required to search uninvolved areas of the building. Anticipation that a continuous water supply would be established may have influenced the tactics and water application used by initial arriving companies.

Protection of the Search Team: Failure to protect the search team with a hoseline was a significant factor in this incident. However, the outcome would likely have been the same if the search team had a hoseline as fire extended from below to cut off their means of egress. A backup line should also have been in place to protect the search team’s egress while they were working above the fire. There was an additional hoseline initially deployed to the doorway on Side A, however, the position and operation of this line while the search team was on Floor 2 was not specified in the report. Without additional tactical changes, the loss of water supply would have precluded effective hoseline support of search operations.

Training in Defensive Search Tactics: Identifying a lack of training in “defensive search tactics” is too narrowly focused. The issue here is significantly broader than stated in the report and should be restated as lack of situational awareness. This causal factor fails to identify the lack of situational awareness on the part of the search crew, the incident commander, and others on the fireground to developing and potential fire conditions and water supply limitations. This lack of situational awareness is likely due to inadequate training in fire behavior and applied fire dynamics (rather than simply inadequate training in defensive search tactics).

Use of a TIC: Undoubtedly effective use of a TIC can speed search operations. However the NIOSH report indicated that visibility was not excessively compromised during the initial stages of search on both floors 1 and 2. Reducing the time required to complete the search could have been influenced by use of a TIC, by assigning a separate crew to perform fire control on Floor 1 of Exposure B and allowing Firefighter Holmes and Lieutenant King to focus on primary search or by both of these actions. While technology may useful in improving firefighter safety, it is important to not simply look for a technological solution to a problem which can be substantively related to human factors such as situational awareness, communications, and decision-making.

Tactical Ventilation: The location, sequence, and lack of coordination in ventilation was likely a causal factor (along with failure to protect the means of egress with a hoseline and loss of water supply) in the injury to Lieutenant King and death of Firefighter Holmes. Creation of exhaust openings above the fire created a clear path of travel for hot gases and flames from Floor 1 to Floor 2 via the interior stairs and increased air supply to a fire which was likely ventilation controlled (resulting in an increase in heat release rate (HRR) sufficient to result in flashover. This contributory factor also points to the need for training on the influence of tactical operations (particularly ventilation) on fire behavior.

Communication of Size-Up Information: Size-up information related to the building and possible victim location could have been a significant factor in focusing the location of the search. However, the civilian occupant was not in either unit, but was located (after fire control) behind the door in the foyer. If it was known that the trapped occupant was from the fire unit, it may have appeared that there was no savable life (due to the extent of fire involvement). But this does not preclude the assumption that she may have been confused and gone into the other unit.

Note: There is some difference of opinion between the fire investigator and operational personnel as to the likely location of the victim prior to structural collapse. It is possible that the victim died on Floor 2 of the fire unit and fell to the position where she was found due to structural collapse.

Accountability and Situation Status: Accountability and communication of situation status is critical to the safety of everyone operating on the fireground. Clear communication in advance of the loss of water supply could have influenced the outcome of this incident. When operating off tank water, it is essential to follow a similar philosophy as the Rule of Air Management and retain sufficient water to exit from the hazardous environment. However, it does not appear that the lack of accountability regarding the search team significantly delayed the rescue effort.

My next post will examine the recommendations made in NIOSH Report F-2008-06 and will provide a link to a detailed, written case study based on this incident in PDF format.

Happy Holidays,
Ed Hartin, MS, EFO, MIFireE, CFO

This post continues examination of NIOSH Death in the Line of Duty Report F2008-06. My previous post, Developing & Using Case Studies: Pennsylvania Duplex Fire Line of Duty Death (LODD) emphasized the importance of case studies to individual and organizational learning and presented initial information about the incident which resulted in injury to Lieutenant Scott King and the death of Firefighter Brad Holmes of Pine Township Engine Company.

Figure 1. 132 Garden Avenue-Side Alpha

Note: Fire Department Photo – NIOSH Death in the Line of Duty Report F2008-06. This photo likely illustrates conditions after 0635 (approximately 19 minutes after arrival of the first fire unit, Chief 95).

Firefighting Operations

Command assigned Engine 95 (officer and five firefighters) to fire suppression. They deployed a 1-3/4″� (45 mm) line to the door on Side A, but were unable to make entry due to the volume of fire in the involved unit. Engine 95 also deployed a 2-1/2″� (64 mm) handline to the A/D corner. Both lines were immediately placed into operation. NIOSH Report F2008-06 indicated that the 1-3/4″� line stretched to the door on Side A was “unable to make entry due to heavy fire conditions”�. However, exact placement and operation of the 2-1/2” handline was not specified. This line may have been used to protect Exposure D (a wood frame dwelling approximately 20′ from the fire unit), for defensive fire attack through first floor windows, or both.

Figure 2. Fire Unit and Exposure Bravo Floor 1

Note: This floor plan is based on data provided in NIOSH Report F2008-06 and is not drawn to scale. Windows shown as open are based on the narrative or photographic evidence. Door position is as shown based on information provided by NIOSH Investigator Steve Berardinelli (this differs from the NIOSH report which includes the fire investigators rough sketch showing all doors open). Windows shown as intact are not visible in the available photographs, but may be open due to fire effects or firefighting operations (particularly those in the fire unit).

Second due, Engine 95-2 performed a forward lay from a nearby hydrant and supplied Engine 95 with tank water while waiting for the supply line to be charged.

Engine 85 (chief, lieutenant, and three firefighters) was assigned to primary search and rescue of the trapped occupant. Tasked to conduct primary search in Exposure B, Firefighter Holmes and Lieutenant King were performed a 360^o reconnaissance prior to making entry. While this was being done other members of the company placed a ladder to a window on Floor 2 Side B (see Figure 3). The NIOSH Report does not specify if the search team was aware of ladder placement.

The Officer of Engine 95 vented the window on Floor 1 Side A of Exposure Bravo and observed that the ceiling light was on (indicating that there was limited optical density of the smoke on Floor 1 of the exposure). Firefighter Holmes and Lieutenant King entered through this window (see Figure 2) to conduct primary search of the exposure and observed that the temperature was low and there was limited smoke on Floor 1. Engine 95 passed the search team a 1-3/4″� (45 mm) handline through the window and the search team knocked down visible fire extension and completed their search of the first floor. At this point, Firefighter Holmes and Lieutenant King left the hoseline on Floor 1, went up the stairs to Floor 2 and began a left hand search.

Figure 3. Fire Unit and Exposure Bravo Floor 2

Note: See the prior comments regarding windows and door position.

The Officer of Engine 95 noticed that the search crew had finished their search on the first floor and were advancing to the second floor. He placed a ladder and broke the window on Floor 2, Side A (See Figure 3). He stated that there was not much heat on the second floor because the plastic insulation on the window was not melted, but he did notice heavy black smoke beginning to bank down. The NIOSH Report did not specify the depth of the hot gas layer (down from the ceiling) or the air track at the window that was vented or Floor 1 openings (windows and door).

The hydrant that Engine 95-2 laid in from was frozen as was the hydrant several houses beyond the fire buildingFirst alarm companies used tank water to support initial firefighting operations. The crew from Engine 95-2 began to hand stretch a 3″� line to a working hydrant on a nearby cross street.

After Firefighter Holmes and Lieutenant King partially completed their search of Floor 2, Lieutenant King’s air supply was at one half and Firefighter Holmes was unsure of his air status, so the Lieutenant decided to exit. At approximately the same time, Engine 95 ran out of water and the Command ordered companies to abandon the building with Engine 85 sounding its air horn as an audible signal to do so. The Accountability Officer called for a Personnel Accountability Report (PAR), but received no response from Lieutenant King or Firefighter Holmes.

Almost immediately after Engine 95 ran out of water, conditions changed rapidly decreasing visibility and increasing temperature on Floor 2 of Exposure B and fire involvement of Floors 1 and 2 of both units. With deteriorating conditions on the second floor, Lieutenant King became disoriented and separated from Firefighter Holmes. He radioed for help at 0638 hours. “Help! Help! Help! I’m trapped on the second floor!” In a second radio transmission, Lieutenant King indicated he was at a window on Side D.

Firefighter Rescue Operations

After hearing radio traffic that the search crew could not find their way out and they were by a window the Engine 95 officer accessed a window on Side B Floor 2 (using a ladder previously placed by Engine 85-2). He broke out the window to increase ventilation and attempt contact with the search team.

A crew from Engine 77 was tasked as a second search team and preparing for entry when the IC ordered companies to withdraw. However, when they heard the Lieutenant’s call for help, they immediately went to Side D, not seeing the Lieutenant at the window, they continued to Side B. The officer from Engine 77 climbed the ladder they had placed earlier to attempt contact with the initial search team. There was heavy black smoke coming from this window, but no fire. He straddled the window sill attempting to hear any movement, a PASS device, or voices. He banged on the window sill as an audible signal to the search team, but received no response. He also attempted to locate the search team using a TIC, however, it malfunctioned.

Flames now pushing out the first floor windows of both the unit originally involved in fire as well as Exposure B. Lieutenant King managed to find his way to the staircase, stumbled down the stairs and out the door on Side A. His protective clothing was severely damaged and smoldering. He collapsed in the front yard and told the other firefighters that the victim was trapped on the second floor. The RIT (R87) made entry supported by a hoseline operated from the entry point by Engine 85-2. Firefighter Holmes was located approximately 10′ (3 m) from the top of the stairs (as illustrated in Figure 3). He was semi-conscious and on his hands and knees. The RIT removed Firefighter Holmes via the stairway to Side A. Lieutenant King and Firefighter Holmes were transported to a local hospital where they were stabilized prior to transport to the Mercy Hospital’s Burn Unit in Pittsburgh.

Questions

The following questions provide a basis for examining the second segment of this case study. While limited information is provided in the case, this is similar to an actual incident in that you seldom have all of the information you want.

1. What was the stage of fire development and burning regime in the fire unit when the search team entered the exposure?
2. What Building, Smoke, Air Track, Heat, and Flame (B-SAHF) indictors can be observed in Figure 1?
3. What was the stage of fire development and burning regime in Exposure B when the search team entered?
4. What type of extreme fire behavior event occurred in the exposure, trapping Firefighter Holmes and Lieutenant King? What leads you to this conclusion?
5. What were the likely causal and contributing factors that resulted in occurrence of the extreme fire behavior that entrapped the Firefighter Holmes and Lieutenant King?
6. What self-protection actions might the search team have taken once conditions on Floor 2 of Exposure B began to become untenable?
7. What action could have been taken to reduce the potential for extreme fire behavior and maintain tenable conditions in Exposure B during primary search operations?
8. What was the tactical rate of flow for full involvement of a single unit in this building? (The tactical rate of flow is the flow required for fire control and does not include the flow rate for backup lines.)
9. What factors may have influenced the limited effectiveness of the 1-3/4” and 2-1/2” attack lines deployed by Engine 95?
10. What tactical options might have improved the effectiveness of fire control operations given the available water supply?

My next post will examine the contributing factors and recommendations made in NIOSH Death in the Line of Duty Report F2008-06 and will include a link to a more detailed written case study of this incident in PDF format.

Ed Hartin, MS, EFO, MIFireE, CFO

A few days ago I watched a video clip of a fire officer performing a vent enter search (VES) operation on firevideo.net. Shortly after the officer made entry into the second floor, the room flashed over and he was forced to make emergency egress over a ladder.

Yesterday, I came across the same video clip on vententersearch.com and saw that the Captain involved in the incident had posted his perspective on the event. There were quite a few posts related to this video and it took me a few minutes to find the Captain’s comments. Reading through the posts, I began to think about the nature and purpose of criticism.

Some firefighters can be quite judgemental, particularly when commenting on decisions or actions taken by someone else. This is often painfully evident when reading comments on fire service blogs or forums. I frequently use video clips and written case studies as learning and instructional tools. Often, these involve mistakes or errors in judgment on the part of the participants. However, it is important to remember that it is quite different to sit around the coffee table or in a classroom and discuss an incident than it is to be faced with a parent screaming that their child is trapped on the second floor of a burning building.

Firefighters and fire officers are faced with the need to rapidly assess the situation and make decisions under dynamic conditions and with limited information. Sometimes the outcome is good and in other cases, the outcome is injury or death in the line of duty. These injuries and deaths are unacceptable, but as long as humans are involved in fighting fires, we will occasionally make errors in judgement. The key is to work together to reduce the probability and frequency of these events.

Criticism

A critic is a person who offers reasoned judgment or analysis, value judgment, interpretation, or observation. While is it possible for a critic to agree with what is being criticized, the term is more frequently applied with someone who disagrees.

Criticism can be constructive or destructive. Constructive criticism is compassionate and respectful. This is often the case when we receive useful feedback from a trusted colleague, friend, coach, or teacher. Constructive feedback is essential to participatory learning. Destructive criticism on the other hand serves to derogate and destroy someone’s work, reputation and self-esteem on whatever level it might be. Destructive criticism might be intentional or done out of ignorance and foolishness.

When criticism is raised, some firefighters say if you weren’t there you have no room to comment (negatively) or take offense when questions are raised about the appropriateness of the actions taken by firefighters who have been injuured or died in the line-of-duty. I strongly disagree with this position. It is essential that we examine these events from a constructively critical perspective to identify the lessons learned.

Decisions made under stress are influenced by many factors, including individual values, organizational culture, experience, training, and education. Photographs and video clips of fireground operations do not lay this foundation nor do they provide situational context such as reported information (e.g., persons trapped) or conditions outside the view of the camera.

VES and Emergency Egress

When using Vent, Enter, and Search (VES); firefighters make entry directly into threatened compartments from the exterior and isolate that compartment by closing the door and then conduct a primary search of that single compartment and exit throught the entry point/ventilation opening. This is a potentially high risk tactic that requires an ability to read the fire and experienced judgment related to both fire conditions and potential for rapid fire progression into the compartment to be searched. The following incident involved VES at a residential structure where rapid fire progress required the Captain conductin the search to perform emergency window egress from a second floor window onto a ladder.

Companies were dispatched to a residential fire at 0400 hours with persons reported. On arrival, cars were observed in the driveway and neighbors reported the likely location of a trapped occupant on the second floor.

Given fire conditions on Floor 1, the Captain of the first in truck, a 23 year vetran, determined that Vent, Enter, and Search (VES) was the best option to quickly search and effect a rescue. In his post on vententersearch.com, Captain Van Sant provided the following information about his observations and actions:

When we vent[ed] the window with the ladder, it looks like the room is burning, but the flames you see are coming from the hallway, and entering through the top of the bedroom doorway. Watch it again and you’ll see the fire keeps rolling in and across the ceiling.

When I get to the window sill, the queen-sized bed is directly against the window wall, so there is no way to check the floor. Notice that you continue to see my feet going in, because I’m on the bed.

Believe me, in the beginning, this was a tenable room both for me and for any victim that would have been in there…

My goal was to get to the door and close it, just like VES is supposed to be done. We do it successfully all the time.

When I reached the other side of the bed, I dropped to the floor and began trying to close the door. Unfortunately, due to debris on the floor, the door would not close.

Conditions were still quite tenable at this point, but I knew with the amount of fire entering at the upper level, and smoke conditions changing, things were going to go south fast.

I kept my eyes on my exit point, and finished my search, including the closet, which had no doors on it. Just as I was a few feet from the window, the room lit off…

The following video clip illustrates conditions encountered at this residential fire:

Find more videos like this on firevideo.net

Things to Think About

Incidents in which persons are reported present considerable moral pressure to take action. The International Association of Fire Chiefs (IAFC) Rules of Engagement for Structural Firefighting and Acceptability of Risk states:

All firefighting and rescue operations involve an inherent level of risk to firefighters.

A basic level of risk is recognized and accepted, in a mesured and controlled manner, in efforts that are routinely employed to save lives and property. These risks are not acceptable in situations where there is no potential to save lives or property.

A higher level of risk is acceptable only in situatios where there is a realistic potential to save known endangered lives. This elevated risk must be limited to operations that are specifically directed toward rescue and where there is a realistic potential to save the person(s) known to be in danger.

If you were faced with the circumstances described by Captain Van Sant and observed in the video clip:

• In general, do you feel that VES an acceptable tactic when there are potentially savable lives? Why or why not?
• Would you have initiated VES operations in this situation? Why or why not?
• Based on conditions observed prior to entry, would you have committed to entering the room as Captain Van Sant did? Why or why not?
• If you were the firefighter on the ladder outside the window, what action would you take while your crew member conducted the search?

The safety of firefighters or officers engaged in VES is dependent in part on the ability to close the door to the room being searched. This use of anti-ventilation changes the ventilation profile, permitting smoke to clear from the room, but reducing potential for fire exension into that compartment. In many cases this can be accomplished quickly, but in other situations the door cannot be closed (as occurred in this incident) or there may be no door present.

• If you encountered this situation, what action would you take?
• Under what circumstances would you discontinue the search to immediately exit the compartment?
• What other strategies might be appropriate under these circumstances

Each of these questions focuses on what you would do if faced with this situation. It is important not to criticize simply for the purpose of pointing out others errors. The value in thinking critically is to help ourselves and others become more skilled at our craft. As Theodore Roosevelt observed:

Criticism is necessary and useful; it is often indispensable; but it can never take the place of action, or be even a poor substitute for it. The function of the mere critic is of very subordinate usefulness. It is the doer of deeds who actually counts in the battle for life, and not the man who looks on and says how the fight ought to be fought, without himself sharing the stress and the danger.

Entering a burning building to attempt a rescue takes courage. Not doing so, in the face of tremendous moral pressure when conditions and circumstances preclude savable lives also takes courage. Act on the basis of your knowledge, skill, and experience.

Ed Hartin, MS, EFO, MIFireE, CFO

This post is a continuation of my feedback to the National Institute for Occupational Safety and Health that will be presented at the public stakeholder meeting conducted in Chicago, IL on 19 November 2008. My recommendations are presented in the form of an analysis of NIOSH Report F2007-29. This incident resulted in the death of Captain Kevin Williams and Firefighter Austin Cheek of the Noonday Volunteer Fire Department.

This post continues with discussion the NIOSH reports examination of the influence of ventilation in this incident and provides specific recommendations for improvement of the NIOSH Firefighter Fatality Investigation and Prevention Program.

Tactical Ventilation

The NIOSH report makes a general recommendation that “fire departments should ensure that properventilation is done to improve interior conditions and is coordinated with interior attack”� [emphasis added]. However, the report is misleading and fails to address key issues related to tactical ventilation, its effective application, and its tremendous influence fire behavior.

NIOSH Report F2007-29 indicated that positive pressure ventilation was initiated prior to the second entry by the initial attack crew (a significant difference from the information provided in the Texas State Fire Marshal’s report). However, no mention is made of any action (or lack thereof) to create an adequate exhaust opening for effective horizontal positive pressure ventilation. While advising that ventilation needs to be proper, it would be helpful to provide more specific guidance. Lack of an adequate exhaust opening prior to pressurizing the building has been a major factor in a number of incidents in which application of positive pressure resulted in extreme fire behavior such as ventilation induced flashover or backdraft. Positive Pressure Attack for Ventilation and Firefighting (Garcia, Kauffmann, & Schelble, 2006), Fire Ventilation (Svensson, 2000), and Essentials of Firefighting (IFSTA, 2008) all emphasize the importance of creating an adequate exhaust opening prior to application of positive pressure.

The NIOSH report pointed out that smoke pushed out the inlet and overrode the effects of the blower, but attributed this to the presence of an attic floor that interfered with vertical ventilation rather than the lack of an adequate exhaust opening for the initial horizontal ventilation.

The PPV fan and vertical ventilation had little effect due to an attic floor being installed. At 0231 Chief #2 had horizontally vented the window on the D side near the A/D corner.

In this incident, ventilation was being performed while the interior attack crew was already inside working. When the ventilation was completed, minimal smoke was pushed out of the vented hole but dark smoke pushed out of the front door, in spite of the fact that a PPV fan was set up at the front door. Note: The dark smoke pushing out the door indicated that the conditions were worsening and the vertical ventilation was not impacting the fire.

In addition, the report fails to note that the opening made on Side D near the AD Corner placed the attack team between the fire and an exhaust opening. As with lack of an adequate exhaust opening, this has been demonstrated to have the potential for disastrous consequences (see NIOSH Death in the Line of Duty F2004-02).

Floor Plan Illustrating the Position of Captain Williams and Firefighter Cheek

Texas State Fire Marshal’s Office Firefighter Fatality Investigation Report FY 07-02

Extreme Fire Behavior

Command ordered companies to abandon the building at 0234 hours using three air horn blasts as an audible signal. The NIOSH report indicated that heavy fire “continued to roll out the front door”� but it is unclear how soon this occurred after smoke conditions at the doorway changed.

NIOSH Report F2007-29 does not clearly identify that extreme fire behavior was a causal or even contributory factor in the deaths of Captain Williams and Firefighter Cheek. It simply states that they died as a result of smoke inhalation and thermal burns.

NIOSH Recommendations

NIOSH made six recommendations based on analysis of the incident in which Captain Williams and Firefighter Cheek lost their lives. Several of these recommendations focused on factors that may have contributed to these two LODD. These included radio communications equipment and procedures, accountability, rapid intervention, and the importance of mutual aid training. Two recommendations were more directly related to causal factors: The importance of ongoing risk assessment and use of proper and coordinated ventilation. However, these broad recommendations miss the mark in providing useful guidance in minimizing the risk of similar occurrences.

Ensure that the IC conducts a risk-versus-gain analysis prior to committing to interior operations and continue the assessment throughout the operation.

This statement is necessary but not sufficient. Size-up and risk assessment is not only the responsibility of the incident commander. All personnel on the fireground must engage in this process within the scope of their role and assignment. Understanding practical fire dynamics is critical to firefighters’ and fire officers’ ability to recognize what is happening and predict likely fire behavior and the influence of tactical operations. To effectively address this issue, NIOSH death in the line of duty reports must be explicit and detailed with regards to key fire behavior indicators observed, subsequent fire behavior phenomena, and the influence of the action or inaction of responders on fire development.

Fire departments should ensure that proper ventilation is coordinated with interior attack.

NIOSH Report 2007-29 focused on the ineffectiveness of the vertical ventilation, but failed to recognize the impact of the sequence of action (i.e. pressurization of the building and creation of exhaust openings), inadequacy of initial exhaust openings, and eventual location of exhaust openings in relation to the operating position of Captain Williams and Firefighter Cheek.

As with situational awareness, effective tactical operations are grounded in training, education, and experience. The incident commander and crews tasked with carrying out tactical ventilation must understand how these tactics influence the fire environment and fire behavior. As with size-up and risk assessment, this is dependent on an understanding of practical fire dynamics.

Other than indicating that ventilation must be coordinated with interior attack, the NIOSH report did not speak to fire control operations conducted during this incident. From the building floor plan and information presented in both the reports by NIOSH and the Texas State Fire Marshal, it appears that the fire was shielded and direct attack was not possible from the position of the first attack team nor the position reached by Captain Williams and Firefighter Cheek. The Fire Marshal’s report indicated that the initial attack team “penciled”� the ceiling to control flames overhead and experienced disruption of the hot gas layer and an increase in temperature at floor level.

Just as ventilation must be appropriate and coordinated with interior fire attack, fire control must also be appropriate and coordinated with tactical ventilation. Cooling the hot gas layer is an appropriate tactic to create a buffer zone and increase the safety of the attack team as they access a shielded fire. However, penciling (use of an intermittent application of a straight stream) the ceiling is an ineffective method of cooling the hot gas layer and results in excessive steam production. In addition, cooling the hot gas layer is not an extinguishment technique; it must be integrated with other fire control methods such as a direct attack on the seat of the fire.

NIOSH death in the line of duty reports must explicitly address the effect of tactical operations, particularly where effectiveness or ineffectiveness was a contributing or causal factor in the LODD.

The Way Forward

While this assessment has been quite critical of NIOSH’s investigation of traumatic fatalities involving extreme fire behavior, it is important to emphasize that with all its faults, the Firefighter Fatality Investigation and Prevention program is a tremendous asset to the fire service.

The following recommendations are made to further strengthen and improve the quality of this program and the utility of recommendations made to reduce the risk of firefighter line of duty deaths as a result of extreme fire behavior during structural firefighting operations:

• Emphasize the criticality of understanding fire behavior, causal factors in extreme fire behavior, and the influence of tactical operations such as fire control and ventilation.
• Increase attention to building, smoke, air track, heat, and flame indicators when investigating incidents which may have involved extreme fire behavior as a causal or contributing factor in LODD.
• Examine training in greater detail, with specific emphasis on fire behavior, situational assessment, realistic live fire training, and crew resource management.
• Provide fire behavior training to all NIOSH investigators to improve their understanding of fire development, extreme fire behavior phenomena, and the impact of tactical operations.
• Include a fire behavior specialist on the investigation team when investigating incidents that may have involved extreme fire behavior as a causal or contributing factor.
• Initiate investigations quickly to avoid degradation of the quality of information obtained from the individuals involved in the incident and other witnesses.

Ed Hartin, MS, EFO, MIFireE, CFO

References

National Institute for Occupational Safety and Health (NIOSH). (2008). Death in the line-of-duty… Report 2007-29. Retrieved November 14, 2008 from NIOSH http://www.cdc.gov/NIOSH/FIRE/reports/face200729.html.

Texas State Fire Marshal’s Office (2008). Firefighter fatality investigation FY 07-02. Retrieved November 14, 2008 from http://www.tdi.state.tx.us/reports/fire/documents/fmloddnoonday.pdf

Svensson, S. (2000). Fire ventilation. Karlstad, Sweden: Swedish Rescue Services Agency

Garcia, K., Kauffmann, R., & Schelble, R. (2006). Positive pressure attack for ventilation & firefighting. Tulsa, OK: Pen Well

International Fire Service Training Association. (2008) Essentials of Firefighting (5th ed). Stillwater, OK: Fire Protection Publications.

Public Stakeholder Meeting

On 19 November 2008, National Institute for Occupational Safety and Health (NIOSH) will conduct a public stakeholder meeting to gather input on the Firefighter Fatality Investigation and Prevention Program. This meeting has a similar focus to one held on 22 March 2006 in Washington DC. At the 2006 stakeholder meeting, NIOSH received Input from a diverse range of fire service stakeholders. Feedback was extremely supportive of the program, but provided input on potential improvements to this extremely important program. In 2006, I gave a brief presentation that focused on several key issues:

• The upward trend in the rate of firefighter fatalities due to trauma during offensive, interior firefighting operations.
• Failure of NIOSH to adequately address fire behavior and limited understanding of fire dynamics as a causal or contributing factor in these fatalities.

The issues that I raised at the 2006 stakeholder meeting continue to be a significant concern. In 2007, extreme fire behavior was a causal or contributing factor in 17 firefighter line of duty deaths (LODD) in the United States. Where these incidents were investigated by NIOSH, the investigations, subsequent reports, and recommendations did not substantively address the fire behavior phenomena involved nor did they provide recommendations focused on improving firefighters and fire officers understanding of practical fire dynamics.

Ongoing Challenges

In the 20 months since the 2006 stakeholder meeting, NIOSH has implemented a number of stakeholder recommendations. However, Death in the line of duty reports continue to lack sufficient focus on fire behavior and human factors issues contributing to traumatic fatalities during offensive, interior firefighting operations.

Where these reports could provide substantive recommendations for training and operations that would improve firefighter safety, they continue to provide general statements reflecting good practice. While the recommendations contained in NIOSH Death in the line of duty reports, are correct and critically important to safe and effective fireground operations, they frequently provide inadequate guidance and clarity.

In incidents involving extreme fire behavior, investigators frequently fail to adequately address the fire behavior phenomena involved and the implications of the action or inaction of responders. In addition, while training is addressed in terms of national consensus standards or standard state fire training curriculum, there is no investigation as to how the level of training in practical fire dynamics, fire control, and ventilation strategies and tactics may have impacted on decision making.

Presentation of these issues in general terms does not provide sufficient clarity to guide program improvement. Examination of a recent death in the line of duty report will be used to illustrate the limitations of these important investigations and reports in incidents where extreme fire behavior is involved in LODD.

Death in the line of duty… F2007-29

There are many important lessons to be learned from this incident and the limited information presented in this report. However, this analysis of Report F2007-29 focuses on fire behavior and related tactical decision-making. This analysis is completed with all due respect to the individuals and agencies involved in an effort to identify systems issues related to the identification and implementation of lessons learned from firefighter fatalities.

On August 3, 2007 Captain Kevin Williams and Firefighter Austin Cheek of the Noonday Volunteer Fire Department lost their lives while fighting a residential fire. Neither this information nor any reference to the report on Firefighter Fatality Investigation FY 07-02 released by the Texas State Fire Marshal’s Office was included in NIOSH Death in the line of duty report F2007-29. This is critical to locating additional information regarding the incident. Even more importantly, it is important to remember that firefighter LODD involve our brother and sister firefighters, not simply “Victim #1″� and “Victim #2”.

Reading the Fire

This incident involved a 2700 ft², wood frame, single family dwelling. The fire was reported at 0136 and the first unit arrived on scene at 0150. The crew of the first arriving engine deployed a 1-3/4″� (45 mm) hoseline and positive pressure fan to the door on Side A. NIOSH Report F2007-29 reported that the attack team made entry at 0151 but backed out a few minutes later due to flames overhead just inside the front door and that positive pressure was initiated at 0156 prior to the attack team re-entering the building.

However, the Texas State Fire Marshal’s Report FY 07-02 indicated the following:

Flint-Gresham Engine 1 arrived on scene at 01:50:21 positioning short of Side A� and reported, “On location, flames visible.”�

Firefighters Joshua Rawlings and Ben Barnard of the Flint-Gresham VFD pulled rack line 2, a 200� long 1.3/4” (45 mm) � line, to the front door on Side A.� Flint-Gresham VFD Firefighter Robles conducted a quick survey of the north side and then positioned the vent fan at the front door to initiate Positive Pressure Ventilation (PPV). Robles stated that the PPV was set and operating prior to entry by the first attack team. Robles stated that he started to survey the south side and noted heavy black smoke from the top half of a broken window. He stated that he reported this to the IC.

Flint-Gresham Firefighters Barnard (nozzle) and Rawlings (backup) entered through the open front door and advanced 8-10 feet on a left hand search. This attack team noted flames rolling across the ceiling moving from their left to their right as if from the attic. Rawlings stated that flames were coming out of the hallway at the ceiling area and around the corner at a lower level. Barnard reported the hottest area at the hallway. The interior attack team then backed out to the front doorway and discussed their tactics. After a brief conversation, Rawlings took the nozzle with Barnard backing him and they re-entered. They entered approximately 10 feet and encountered flames rolling from their left to their right. They used a “penciling technique”� aimed at the ceiling to cool the thermal layer. Rawlings reported in interview that there was an increase in heat and decrease in visibility as the thermal layer was disrupted and heat began to drop down on top of them.

There is an inconsistency between the NIOSH and Texas State Fire Marshal’s reports regarding the timing of the positive pressure ventilation. The NIOSH report indicates that positive pressure was applied between the first and second entries by the attack team. However, in the Fire Marshal’s report, Firefighter Robles is quoted as stating that positive pressure was applied before entry. This seems to be a minor point, but if effective, positive pressure ventilation would have significantly changed the fire behavior indicators observed from the exterior and inside the building. Recognition of this discrepancy along with a sound understanding of practical fire dynamics would have pointed to the ineffectiveness of tactical ventilation and potential for extreme fire behavior.

The NIOSH report did not identify the fire behavior indicators initially observed by Firefighter Robles or the attack team, nor did they draw any conclusions regarding the stage of fire development, burning regime (fuel or ventilation controlled), or effectiveness of the positive pressure ventilation.

NIOSH Report F2007-29 did not speak to the fact that none of the first arriving personnel verified the size and adequacy of the existing ventilation opening, the potential implications of inadequate exhaust opening size, and the need to verify that the positive pressure ventilation was effective prior to entry. In addition, the initial attack crew observed flames moving toward the point of entry, which would not be likely if the positive pressure ventilation was effective. However, no mention was made in the NIOSH report regarding conditions inside building and the observations of the attack team.

Window size is not specified, but it is likely that the opening was significantly less than the area of the inlet being pressurized by the fan. Inadequate exhaust opening area leads to excessive turbulence, mixing of hot smoke (fuel) and air, and can lead to extreme fire behavior such as vent induced flashover or backdraft. Recognition of this discrepancy along with a sound understanding of practical fire dynamics would have pointed to the ineffectiveness of tactical ventilation and potential for extreme fire behavior.

In reading this case study, it would be useful for the reader to be able to make a connection between key fire behavior indicators, the decisions made by on-scene personnel, and subsequent fire behavior. The NIOSH report did not identify the indicators initially observed by interior or exterior crews, nor did it draw any conclusions regarding the stage of fire development, burning regime (fuel or ventilation controlled), or effectiveness of the positive pressure ventilation, all of which were likely factors influencing the outcome of this incident.

NIOSH Report F2007-29 indicated that the attack team exited the building at 0213 due to low air and reported that the fire was knocked down, identified the location of a few hot spots, and that smoke conditions were light. The report follows to indicate that one of the chief officers did a walk around two minutes later and observed smoke in all the windows and smoke coming from the B/C and C/D corners of the structure. However the Texas State Fire Marshal’s Report 07-02 stated:

Firefighters Rawlings and Barnard penciled the rolling flames in the thermal layer until Rawlings’s low air alarm sounded. The Incident Commander, Captain Williams and Firefighter Cheek met Firefighters Rawlings and Barnard at the front door and a briefing occurred. Firefighters Rawlings and Barnard reported to Asst. Chief Baldauf they had the hot spots out. Rawlings stated in a later interview that they told Williams and Cheek they knocked down the fire and only overhaul was needed.

At 02:13, Captain Williams and Firefighter Cheek entered the structure as attack team 2, using the same line previously utilized by Firefighters Rawlings and Barnard.

Exterior crews from Noonday and Bullard started horizontal ventilation by breaking a window out on Side C (north side). Noonday Chief Gary Aarant performed a walk around, then reported heavy smoke from the B/C,and C/D� corners and at 02:15:51 asked if vertical ventilation had been started. Command then gave the order to begin vertical ventilation.

Understanding what occurred in this incident requires more than the cursory information provided in the NIOSH report. Developing the understanding of critical fire behavior indicators is essential to situational awareness. Discussion of fire behavior indicators and their significance in NIOSH reports would provide an excellent learning opportunity. For example, in this incident, the difference between “smoke” as described in the NIOSH report and “heavy smoke” as reported in the Texas State Fire Marshal’s report is likely a significant difference in assessment of conditions from the exterior of the building (particularly if this is a change in conditions).

NIOSH Report F2007-29 made brief mention of smoke discharge from the point of entry which was being used as the inlet for application of positive pressure. “At 0236 hours, heavier and darker smoke began pushing out of the entire front door opening and overriding the PPV fan”. However, the report does not speak to the significance of this indicator of impending extreme fire behavior.

The Texas State Fire Marshal’s Report 07-02 included a series of photographs provided by the Bullard Fire Department which provided a dramatic illustration of these key smoke and air track indicators. Inclusion of these photographs in the NIOSH report would have aided the reader in recognizing this key indicator of ineffective tactical ventilation and imminent potential for extreme fire behavior.

Photo of Conditions on Side A at 0210

Bullard Fire Department Photo/Texas State Fire Marshal’s Report

Photo of Conditions on Side A at 0217

Bullard Fire Department Photo/Texas State Fire Marshal’s Report

Photo of Conditions on Side A at 0223

Bullard Fire Department Photo/Texas State Fire Marshal’s Report

NIOSH Report F2007-29 addresses the need for the incident commander to conduct a risk versus gain analysis prior to and during interior operations. However, the report does not address the foundational skill of being able to read fire and predict likely fire behavior as a part of that process. In addition, reading the fire and dynamic risk assessment are not solely the responsibility of the incident commander. Everyone on the fireground must be involved in this process within the scope of their role and work assignment. For example, the initial and subsequent attack teams were in a position to observe critical indicators that were not visible from the exterior.

While there is no way to tell, it is likely that if Captain Williams and Firefighter Cheek recognized the imminent probability of extreme fire behavior or the significance of changing conditions they would have withdrawn the short distance from their operating position to the exterior of the building. Likewise, if the incident commander or others operating on the exterior recognized deteriorating conditions earlier in the incident it is likely that they would have taken action sooner to withdraw the crew working on the interior.

Understanding practical fire dynamics, recognition of key indicators and predicting likely fire behavior is a critical element in situational awareness and dynamic risk assessment. Fire behavior and fire dynamics receive limited focus in most standard fire training curricula. It is important that NIOSH examine this issue when extreme fire behavior is a causal or contributing factor in LODD.

My next post will continue with the analysis of NIOSH Report F2007-29 and will make specific recommendations for program improvement.

Ed Hartin, MS, EFO, MIFireE, CFO

Second only to the great solid stream versus fog debate, ventilation strategies seem to create the most discussion and disagreement among fire service practitioners. Vertical or horizontal; natural, negative, or positive pressure; vent before, during or after fire control? These are all good questions (many of which have more than one answer).

The Importance of Why

BC Kriss Garcia recently published an interesting article titled Education vs. Training in Fire Space Control (Fire Engineering, September 2008) examining the difference between training and education, in particular as it relates to ventilation strategies. Kriss emphasized that we train to improve performance and efficiency, but use education to develop our ability to think and understand not only how, but when, why, and why not. Both are critical to today’s firefighters and fire officers.

Space Control

Firefighters sometimes perform ventilation operations by routine, executing tactics simply based on common practice without thought to the influence of these actions on the fire environment and fire behavior. Kriss emphasizes the importance of understanding the effect of changing the ventilation profile and its relationship to fire control, stating:

Absolute control of the space you are opening is necessary for a safe and effective fire attack. If firefighters cannot control the space with enough direct application of [British thermal unit] Btu -quenching water, they should not be opening the space, encouraging additional free burning.

The concepts included in this brief statement are critical, but could be expanded and clarified a bit.

• Developing and maintaining control of the space is critical to offensive firefighting operations and the survival of civilian fire victims who may be trapped in the building.
• Increasing the air supply to a ventilation controlled fire will increase the heat release rate. Heat release rate is measured in kilowatts (kW) or British thermal units (Btu)/m.
• Water application in liters or gallons per minute (lpm or gpm) must exceed the critical rate of flow based on the heat release rate (kW or Btu/min) developed by the fire.

There are two key differences in this expanded outline of the importance of understanding the influence of changing the ventilation profile: 1) Recognizing and understanding the dominant influence on current fire development, fuel or ventilation. Heat release rate from a fire burning in the ventilation controlled burning regime will increase if the fire receives additional air. 2) Water application (lpm or gpm) must be sufficient to overcome the heat release rate from the fire. While it is common to hear firefighters say that gpm must overcome Btu, this is not completely correct. Btu is a measure of energy much the same as liters or gallons is a measure of the volume of water. Kilowatts (1000 joules/second) or Btu/minute are a measure of heat release rate as lpm or gpm are a measure of water application rate.

Tactical ventilation is the other element of space control. Smoke contains unburned pyrolizate and flammable products of incomplete combustion, and as such is fuel. Hot fuel gases overhead can be cooled, providing a buffer zone around the nozzle team, but only when smoke is removed through tactical ventilation is this hazard fully mitigated.

Understanding is Critical

The difficulty that some firefighters have in accepting positive pressure ventilation or positive pressure attack is frequently rooted in a lack of understanding. In some cases, this based on dogmatic attachment to other tactical approaches. In other cases, it is a result of too much training (how to do it) and not enough education (why, why not, and when). Kriss emphasizes the value of positive pressure ventilation and the need to balance training and education to develop both skills proficiency and understanding.

Friendly Criticism

The concluding paragraph of Kriss’s article Education vs. Training in Fire Space Control (Fire Engineering, September 2008) makes two strong statements.

Regardless of the approach we use to safely control fires, we must maintain as the basis of all discussions our ability to control the fire space prior to opening it. The most dramatic means of accomplishing this is through control of the interior environment with [positive pressure attack] PPA and direct water application.

I am fully in agreement with the first sentence. Maintaining control of the fire space is absolutely critical to safe and effective offensive operations. However, the second sentence, which so emphatically supports PPA integrated with direct attack without qualifying the conditions under which this tactic should or should not be used, could be a bit misleading. Under many conditions, PPA and direct attack will be extremely effective. In other circumstances, these tactics are not appropriate. For example, Positive Pressure Attack for Ventilation and Firefighting by Garcia, Kauffmann, and Schelble, identifies several contraindications to use of PPA, inclusive of victims in the exhaust opening or other area which may be threatened and extremely ventilation controlled fire conditions which may present risk of backdraft.

The metaphor of the silver bullet applies to any straightforward solution perceived to have extreme effectiveness. The phrase typically appears with an expectation that some new technology or practice will easily cure a major prevailing problem. (Wikipedia)

In firefighting there are no silver bullets. Increased understanding of the theoretical foundations of fire behavior and the influence of ventilation and applied research such as that done by the National Institute for Standards and Technology are the key to effective use of ventilation strategies and improving the safety and effectiveness of fireground operations.

Firefighters should not uncritically accept current practice. Neither should firefighters accept new or different approaches without the same thoughtful and critical examination. Not just what and how, but why! Kriss’s Positive Pressure Attack website has a wide range of resources related to positive pressure ventilation and positive pressure attack. As Kris advises, both education and training are critical to safe and effective firefighting. Positive pressure attack is an extremely powerful tool when used correctly, be a student of your craft and learn not just what and how, but why!

Kris also published an article titled The Power of Negative Thinking in October issue of FireRescue magazine. This article takes a look at how pressure differences inside and outside the fire building influence ventilation. This interesting article will be the focus of a future post.

Ed Hartin, MS, EFO, MIFireE, CFO