Posts Tagged ‘reading the fire’

In Reading the Fire: How to Improve Your Skills, I discussed building a concept map of fire behavior indicators as a method to increase competence in reading the fire. Construction of a concept map increases awareness of key indicators and understanding their interrelationships. I am working through this process along with you, with the latest revision to my concept map. Thus far, I have examined Building Factors, the first category of indicators in the B-SAHF (Building, Smoke, Air Track, Heat, and Flame) organizing scheme. For review of the discussion of building factors and revision of this segment of my concept map see the following three posts:

Reading the Fire: Building Factors

Reading the Fire: Building Factors Part 2

Reading the Fire: Building Factors Part 3

Focus Question

As pointed out at the start of this project, a concept map starts with a focus question that specifies the problem or issue that the map is intended to help resolve. The fire behavior indicators (FBI) concept map starts with the following focus question:

What building, smoke, air track, heat, and flame indicators
provide clues to current and potential fire behavior?

It is important to remember that a concept map is never finished. After you develop the first draft, it is always necessary to revise the map to increase clarity or add important concepts that you discover as work continues.

In the next few posts in the series, we will apply this focus question to smoke indicators.

Smoke Versus Air Track

There are a number of interrelationships between Smoke and Air Track. However, in the B-SAHF organizing scheme they are considered separately. As we begin to develop or refine the map of Smoke Indicators it is useful to revisit the difference between these two categories in the B-SAHF scheme as outlined in Reading the Fire: Building Factors

Smoke: What does the smoke look like and where is it coming from? This indicator can be extremely useful in determining the location and extent of the fire. Smoke indicators may be visible on the exterior as well as inside the building. Don’t forget that size-up and dynamic risk assessment must continue after you have made entry!

Air Track: Related to smoke, air track is the movement of both smoke (generally out from the fire area) and air (generally in towards the fire area). Observation of air track starts from the exterior but becomes more critical when making entry. What does the air track look like at the door? Air track continues to be significant when you are working on the interior.

Getting Started

When reading the fire it is important not to focus on a single indicator or category of indicators. However, Smoke Indicators often provide critical information about stages of fire development, burning regime, and differences in conditions throughout the building.

As always in developing a concept map it is important to move from general concepts to those that are more specific. Basic smoke indicators may include location, optical density (thickness), color, physical density (buoyancy), and volume as illustrated in Figure 1. However, you may choose to approach this somewhat differently.

Figure 1. Basic Smoke Indicators

Developing the Detail

Expanding the map requires identification of additional detail for each of the fundamental concepts. If an idea appears to be obviously related to one of the concepts already on the map, go ahead and add it. If you are unsure of where it might go, but it seems important, list it off to the side in a staging area for possible additions. Download a printer friendly version of Smoke Indicators to use as a starting point for this process.

Next Steps

Remember that the process of contracting your own map is likely as important as the (never quite) finished product. The following steps may help you expand and refine the Smoke Indicators segment of the map:

• Look at each of the subcategories individually and brainstorm additional detail. This works best if you collaborate with others.
• Have a look at the following video clip using your partially completed map and notes as a guide to identifying important smoke indicators. Think about what the smoke indicators mean and visualize developing fire conditions inside the building.

The following video has some excellent smoke indicators towards the middle of the clip that may aid in developing and refining your Smoke Indicators concept map.

Step Back and Look at the Entire Picture

I would not want to waste the opportunity to engage with the rest of the B-SAHF indicators. Download and print the B-SAHF Worksheet. Consider the information provided in each of the short video clips and complete the worksheet for each. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators and then answer the following five standard questions?

1. What additional information would you like to have? How could you obtain it?
2. What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
3. What burning regime is the fire in (fuel controlled or ventilation controlled)?
4. What conditions would you expect to find inside this building?
5. How would you expect the fire to develop over the next two to three minutes

Twitter

While I did not get any response from the questions I posted on Twitter related to Building Factors, I will continue this practice as we explore smoke indicators. Have a look [http://twitter.com/edhartin] and join in by responding to the questions. End your comments related to Fire Behavior Indicators on Twitter with #B-SAHF (this hashtag simplifies searching for FBI related posts). In addition to B-SAHF questions, I also post links to video clips and fire behavior related new items on Twitter.

Ed Hartin, MS, EFO, MIFireE, CFO

While I have not had much input (via Twitter or post comments), I have been working on the Building Factors map to include factors related to the surrounding environment and to revise fire protection systems, construction, fuel, size, and ventilation profile.

Surrounding Environment

Previous versions of the fire behavior indicators (FBI) concept map considered wind effects as a component of air track (which it influences significantly), but did not consider other environmental influences on fire behavior. After considerable thought, I recognized that building factors (and to some extent all of the FBI) can be viewed like Matryoshka Dolls (nested Russian dolls) when used to think about a single compartment, the building, or the building in its surrounding environment.

Environmental factors include exposures (which fire can extend from or to), ambient weather conditions, and terrain. Weather and terrain likely deserve a bit of explanation. While these factors are recognized as major players in wildland fire behavior, their influence is often not as quickly recognized in the built environment. Wind is likely the greatest meteorological concern when dealing with compartment fires. As discussed in prior posts (Wind Driven Fires, NIST Wind Driven Fire Experiments: Establishing a Baseline, Evaluating Firefighting Tactics Under Wind Driven Conditions), wind driven fires present a significant threat to firefighters. However, while buildings are generally designed to minimize the impact of temperature, humidity, and precipitation on their occupants, these factors can influence fire behavior directly or indirectly. For example, combustible exterior surfaces (e.g., wood shingle or shake roofs) present an increased hazard if humidity is low and ambient temperature is high. The influence of terrain may not be quite as obvious. In some cases, terrain may influence wind effects and in others slope may result in differences in elevation on each side of the building. When unrecognized, this has been a factor in a number of firefighter fatalities due to the resulting air track and path of fire spread from lower, to upper floors. For example see NIOSH (1999) Death in the Line of Duty Report F99-21 and Simulation of the Dynamics of the Fire at 3146 Cherry Road NE, Washington D.C. (NIST, 2000).

Fire Protection Systems

Fire suppression systems such as automatic sprinklers can obviously have a direct influence on fire development in a protected compartment. Similarly, fire detection may reduce the time between ignition and intervention by the fire department. However, prior versions of the FBI concept map did not include passive fire protection such as fire rated separations (other than generically as compartmentation).

Construction & Fuel

Prior versions of the FBI map linked Building to Contents and Construction. I have changed this to consider both contents and construction as fuel, while maintaining a link between building factors and construction as there are other facets of construction that can influence fire behavior. However, this area of the map remains a bit tentative (with more work to be done). Other changes to this part of the map include the addition of fire load density (kJ/m2) and increasing clarity of the concepts related to flow rate requirements for fire control.

Size

The concept of size can be a bit confusing as it applies to individual compartments (habitable or void spaces), interconnected compartments, and the entire building. Refinements include the addition of void spaces and normal door position to the concept of compartmentation.

Ventilation Profile

Thermal performance of potential openings has been added to ventilation profile, recognizing that single pane windows perform considerably different than multi-pane, energy efficient windows under fire conditions. In addition, a note was added to clarify that ventilation may be from compartment to compartment or from the building to the external environment.

Figure 1. Building Factors Concept Map v5.2.2.1

You can also download a larger, printer friendly version of the Building Factors Concept Map v5.2.2.1 (including notes made during development). Several colleagues who have had a look at this map observed that it is extremely complicated. While this is true, if you take the time to examine each of the factors and give some thought to the interrelated influences on fire behavior, it becomes a bit clearer. Remember that this is my representation of the concepts, yours will likely be a bit different! As always, feedback is greatly appreciated.

Subsequent posts will examine the rest of the B-SAHF (Building, Smoke, Air Track, Heat, & Flame) organizing scheme for fire behavior indicators.

Ed Hartin, MS, EFO, MIFireE, CFO

References

National Institute for Occupational Safety and Health (NIOSH) (1999) Death in the line of duty report F99-21. Retrieved July 2, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face9921.pdf

National Insitute for Standards and Technology (NIST). Simulation of the Dynamics of the Fire at 3146 Cherry Road NE, Washington D.C. Retrieved July 2, 2009 from http://www.fire.nist.gov/CDPUBS/NISTIR_6510/6510c.pdf

In Reading the Fire: How to Improve Your Skills and Fire Behavior Indicators: Building Factors we started the process of developing a personal fire behavior indicators (FBI) concept map. I am working along with you to expand and refine my FBI Concept Map (Version 5.2.1).

Reading the Fire

I regularly post B-SAHF (Building, Smoke, Air Track, Heat, and Flame) Exercises to provide the opportunity to practice reading the fire. However, photos and video clips can also provide a great opportunity to focus in on a single type of indicator (such as building factors). Dig out the work in progress on your FBI concept map and have a look at the following video clips and focus your attention on building factors.

1. What type of construction was involved? How (or did) this factor influence fire behavior?
2. What other building and occupancy characteristics may have had an impact on fire behavior?
3. Are the factors you identified on your concept map? If not, add them to the map or list them in a staging area until you have determined where they might go on the map.

Los Angeles County Commercial Fire

Vancouver BC Apartment Fire

Los Angeles City Commercial Fire

What additions have you made to your FBI concept map? If you found this useful, poke around on YouTube and continue to apply this method to help you develop and refine the building factors (and other elements) of your map.

Step Back and Look at the Entire Picture

I would not want to waste the opportunity to engage with the rest of the B-SAHF indicators. Download and print three copies of the B-SAHF Worksheet. Consider the information provided in each of the short video clips and complete the worksheet for each. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators and then answer the following five standard questions?

1. What additional information would you like to have? How could you obtain it?
2. What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
3. What burning regime is the fire in (fuel controlled or ventilation controlled)?
4. What conditions would you expect to find inside this building?
5. How would you expect the fire to develop over the next two to three minutes

Next Post

I have spent the last several days attending the Florida State Fire College Live Fire Training Instructor (LFTI) course being delivered at the Oregon Public Safety Academy in Salem, Oregon. My next post will provide an overview and critique of this excellent course.

Ed Hartin, MS, EFO, MIFireE, CFO

Unanticipated smoke explosion and building collapse nearly kills three firefighters.

Portsmouth, VA Near-Miss Incident

Firefighter Eric Kirk gives a firsthand account of a near-miss incident involving a smoke explosion in the June 2009 issue of FireRescue magazine. On a December morning in 2007, firefighters in Portsmouth, Virginia responded to a fire in a church. On arrival, the building was well involved and defensive operations were initiated to protect exposures and confine the fire. Over the course of the fire, smoke extended into an attached, three-story, brick building and formed a flammable fuel/air mixture. Subsequent extension of flames from the church to the interior of the exposure resulted in ignition and explosive combustion of this fuel (smoke)/air mixture.

Incident Photos from PilotOnline.com

Smoke Explosion

This post expands on Smoke is Fuel (Hartin, 2009), a sidebar that I wrote for FireRescue that accompanies Eric’s article examining the Portsmouth, VA smoke explosion incident.

Smoke explosions have resulted in three firefighter fatalities in the United States since 2005, two in Wyoming (see NIOSH Report F2005-13) and one last year in Los Angeles California (NIOSH report pending). In addition, there have been a number of near miss incidents including this one in Virginia and another in Durango, Colorado (see NIOSH Report F2008-02)However, many firefighters have not heard of or misunderstand this fire behavior phenomenon.

The terms backdraft and smoke explosion have typically been used to describe explosions resulting results from confined and rapid combustion of pyrolysis and unburnt products of incomplete combustion. Describing a backdraft incident at a Chatham, England Mattress Store in 1975, Croft (1980) states “this is not an entirely new phenomenon, the first formal description of what have been called ‘smoke explosions’ having been given in 1914” (p. 3).

As an explanation of many contradictory statements in reference to explosions that are reported to have occurred in burning buildings, where it is also testified that explosives were non-existent, we may cite so-called “smoke explosions.”

Distinct from, yet closely allied with explosions of inflammable dust, are explosions caused by the ignition of mixtures of air with the minute particles of unconsumed carbon and invisible gaseous matter in smoke from the imperfect combustion of organic substances…

These “smoke explosions” frequently occur in burning buildings and are commonly termed “back draughts” or “hot air explosions” (Steward, 1914).

As discussed in my earlier post, Fires and Explosions, the term Smoke Explosion was a synonym for Backdraft. In fact, if you look up the definition of smoke explosion in the National Fire Protection Association (NFPA) 921 (2008) Guide for Fire and Explosion Investigation, it says “see backdraft” (p. 921-15). However, today it identifies a different, and in many respects more dangerous extreme fire behavior phenomenon. Smoke (or Fire Gas) Explosion is described in fire dynamics textbooks such as Enclosure Fire Dynamics (Karlsson and Quintiere) and An Introduction to Fire Dynamics (Drysdale) and Enclosure Fires (Bengtsson). Of these, the text Enclosure Fires by Swedish Fire Protection Engineer Lars-Göran Bengtsson provides the best explanation of how conditions for a smoke explosion develop. However, this phenomenon is less well known among firefighters and fire officers. In fact many well known fire service authors continue to use backdraft and smoke explosion interchangeably.

A smoke or fire gas explosion occurs when unburned pyrolysis products accumulate and mix with air, forming a flammable mixture and introduction of a source of ignition results in a violent explosion of the pre-mixed fuel gases and air. This phenomenon generally occurs remote from the fire (as in an attached exposure) or after fire control.

Conditions Required for a Smoke Explosion

The risk of a smoke explosion is greatest in compartments or void spaces adjacent to, but not yet involved in fire. Infiltration of smoke through void spaces or other conduits can result in a well mixed volume of smoke (fuel) and air within its flammable range, requiring only a source of ignition.

Smoke explosions create a significant overpressure as the fuel and air are premixed. Several factors influence the violence of this type of explosion:

• The degree of confinement (more confinement results in increased overpressure)
• Mass of premixed fuel and air in the compartment (more premixed fuel results in a larger energy release)
• How close the mixture is to a stoichiometric concentration (the closer to an ideal mixture the faster the deflagration)

For additional information on transient, explosive, fire phenomena see earlier posts: Gas Explosions and Gas Explosions Part 2.

Indicators Smoke Explosion Potential

It is very difficult to predict a smoke explosion. However, the following indicators point to the potential for this phenomenon to occur.

• Ventilation controlled fire (inefficient combustion producing substantial amounts of unburned pyrolysis products and flammable products of incomplete combustion)
• Relatively cool (generally less than 600^o C or 1112^o F) smoke
• Presence of void spaces, particularly if they are interconnected
• Combustible structural elements
• Infiltration of significant amounts of smoke into uninvolved exposures

Mitigating the Hazard

As with recognizing the potential for a smoke explosion, mitigation can also be difficult. The gases are relatively cool, so application of water into the gas layer may have limited effect. Tactical ventilation to remove the smoke is the only way to fully mitigate the hazard and establish a safe zone. However, use care not to create a source of ignition (such as the sparks created when using an abrasive blade on a rotary saw).

The best course of action is to prevent infiltration of smoke into uninvolved spaces using anti-ventilation (confinement) tactics. Anti-ventilation is the planned and systematic confinement of heat, smoke, and fire gases, and exclusion of fresh air (from the fire). In this case, anti-ventilation may involve pressurizing the uninvolved are to prevent the spread and accumulation of smoke.

Ed Hartin, MS, EFO, MIFIreE, CFO

References

Bengtsson, L. (2001). Enclosure fires. Karlstad, Sweden: Räddnings Verket.

Croft, W. (1980) Fires involving explosions-a literature review. Fire Safety Journal, 3(1), 3-24.

Drysdale, D. (1998). An introduction to fire dynamics (2^nd ed.). New York: John Wiley & Sons.

Hartin, E. (2009, June). Smoke is fuel. FireRescue, 27(6), 54.

Karlsson, B. & Quintiere, J. (2000). Enclosure fire dynamics. Boca Raton, LA: CRC Press.

Kirk, E. (2009, June). Sudden blast: Unanticipated smoke explosion & building collapse nearly kills 3 firefighters. FireRescue, 27(6), 52-54.

National Fire Protection Association. (2008). NFPA 921 Guide for fire and explosion investigations. Quincy, MA: Author.

National Institute for Occupational Safety and Health (NIOSH). (2006) Death in the Line of Duty Report F2005-13. Retrieved June 22, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200513.pdf

National Institute for Occupational Safety and Health (NIOSH). (2009) Death in the Line of Duty Report F2008-02. Retrieved June 22, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200803.pdf

Steward, P. (1914). Dust and smoke explosions, NFPA Quarterly 7, 424-428.

Fire Behavior Indicators – A Quick Review

The B-SAHF (Building, Smoke, Air Track, Heat, & Flame) organizing scheme for fire behavior indicators provides a sound method for assessment of current and potential fire behavior in compartment fires. The following provides a quick review of each of these indicator types.

Figure 1. B-SAHF

Building: Many aspects of the building (and its contents) are of interest to firefighters. Building construction influences both fire development and potential for collapse. The occupancy and related contents are likely to have a major impact on fire dynamics as well.

Smoke: What does the smoke look like and where is it coming from? This indicator can be extremely useful in determining the location and extent of the fire. Smoke indicators may be visible on the exterior as well as inside the building. Don’t forget that size-up and dynamic risk assessment must continue after you have made entry!

Air Track: Related to smoke, air track is the movement of both smoke (generally out from the fire area) and air (generally in towards the fire area). Observation of air track starts from the exterior but becomes more critical when making entry. What does the air track look like at the door? Air track continues to be significant when you are working on the interior.

Heat: This includes a number of indirect indicators. Heat cannot be observed directly, but you can feel changes in temperature and may observe the effects of heat on the building and its contents. Remember that you are insulated from the fire environment, pay attention to temperature changes, but recognize the time lag between increased temperature and when you notice the difference. Visual clues such as crazing of glass and visible pyrolysis from fuel that has not yet ignited are also useful heat related indicators.

Flame: While one of the most obvious indicators, flame is listed last to reinforce that the other fire behavior indicators can often tell you more about conditions than being drawn to the flames like a moth. However, that said, location and appearance of visible flames can provide useful information which needs to be integrated with the other fire behavior indicators to get a good picture of conditions.

It is important not to focus in on a single indicator, but to look at all of the indicators together. Some will be more important than others under given circumstances.

Getting Started

Considering the wide range of different building types and occupancies, developing a concept map of the factors and interrelationships that influence fire behavior is no simple task. As you begin this process, keep in mind that it is important to move from general concepts to more specific details. For example, you might select construction type, contents, size, ventilation profile, and fire protection systems as the fundamental factors as illustrated in Figure 2. (However, you also might choose to approach this differently!).

Figure 2. Basic Building Factors

Remember that this is simply a draft (as will each successive version of your map)! Don’t get hung up on getting it “right”. The key is to get started and give some thought to what might be important. After adding some detail, you may come back and reorganize the map, identifying another basic element. For example, early versions of this map listed Fire Suppression Systems (e.g., automatic sprinklers) as one of the core concepts. However, after adding some detail, this concept was broadened to Fire Protection Systems (e.g., automatic sprinklers, fire detection, and other types of inbuilt fire protection).

Developing the Detail

Expanding the map requires identification of additional detail for each of the fundamental concepts. If an idea appears to be obviously related to one of the concepts already on the map, go ahead and add it. If you are unsure of where it might go, but it seems important, list it off to the side in a staging area for possible additions. For example, area and height are important concepts related to size. However, compartmentation may be related to size or it may be a construction factor. If you are unsure of where this should appear on the map, place it in the Staging Area for now.

Figure 3. Expanding the Map

Next Steps

Remember that the process of contracting your own map is likely as important as the (never quite) finished product. The following steps may help you expand and refine the building factors segment of the map:

• Look at each of the subcategories individually and brainstorm additional detail. This works best if you collaborate with others.
• Take your partially completed map and notes and visit several different types of buildings. Visualize how a fire might develop and what building features would influence this process.
• Examine the incident profiled in the Remember the Past segment of this post and give some thought to how building factors may have influenced fire behavior and the outcome of this incident.

In addition, I am still posing questions related to B-SAHF using Twitter. Have a look [http://twitter.com/edhartin] and join in by responding to the questions. While this is not a familiar tool to most firefighters, I think that it has great potential.

Thanks

I would also like to thank Senior Instructor Jason Collits of the New South Wales (Australia) Fire Brigades and Lieutenant Matt Leech of Tualatin Valley Fire and Rescue (also an Instructor Trainer with CFBT-US, LLC) for their collaborative efforts on extending and refining our collective understanding of the B-SAHF indicators. Jason and Matt have been using Bubbl.us to develop and share their respective maps and I will be integrating their work into future posts on Fire Behavior Indicators.

Figure 4 Jason Collits and Matt Leech

Remember the Past

Yesterday was the eighth anniversary of a tragic fire in New York City that claimed the lives of three members of FDNY as a result of a backdraft in the basement of a hardware store.

June 17, 2001
Firefighter First Grade John J. Downing, Ladder 163
Firefighter First Grade Brian D. Fahey, Rescue 4
Firefighter First Grade Harry S. Ford, Rescue 3
Fire Department City of New York

Fire companies were dispatched to a report of a fire in a hardware store. The first- arriving engine company, which had been flagged down by civilians in the area prior to the dispatch, reported a working fire with smoke venting from a second-story window.

A bystander brought the company officer from the first-arriving engine company to the rear of the building where smoke was observed venting from around a steel basement door. The first-arriving command officer was also shown the door and ordered an engine company to stretch a line to the rear of the building. A ladder company was ordered to the rear to assist in opening the door; Firefighter Downing was a member of this company. The first-due rescue company, including Firefighters Fahey and Ford, searched the first floor of the hardware store and assisted with forcible entry on the exterior.

The incident commander directed firefighters at the rear of the building to open the rear door and attack the basement fire. Firefighters on the first floor were directed to keep the interior basement stairwell door closed and prevent the fire from extending. The rear basement door was reinforced, and a hydraulic rescue tool was employed to open it. Once the first door was opened, a steel gate was found inside, further delaying fire attack.

Firefighters Downing and Ford were attempting to open basement windows on the side of the building, and Firefighter Fahey was inside of the structure on the first floor.

An explosion occurred and caused major structural damage to the hardware store. Three fire-fighters were trapped under debris from a wall that collapsed on the side of the hardware store; several firefighters were trapped on the second floor; firefighters who were on the roof prior to the explosion were blown upwards with several firefighters riding debris to the street below; and fire-fighters on the street were knocked over by the force of the explosion.

The explosion trapped and killed Firefighters Downing and Ford under the collapsed wall; their deaths were immediate. Firefighter Fahey was blown into the basement of the structure. He called for help on his radio, but firefighters were unable to reach him in time.

The cause of death for Firefighters Downing and Ford was internal trauma, and the cause of death for Firefighter Fahey was listed as asphyxiation. Firefighter Fahey’s carboxyhemoglobin level was found to be 63%.

In addition to the three fatalities, 99 firefighters were injured at this incident. The fire was caused when children – two boys, ages 13 and 15 – knocked over a gasoline can at the rear of the hard-ware store. The gasoline flowed under the rear doorway and was eventually ignited by the pilot flame on a hot water heater.

For additional information on this incident, see the following:

NIOSH Death in the Line of Duty Report F2001-23,

Simulation of the Dynamics of a Fire in the Basement of a Hardware Store

Incident Photos by Steve Spak

Ed Hartin, MS, EFO, MIFireE, CFO

References

Grimwood, P., Hartin, E., McDonough, J., & Raffel, S. (2005). 3D firefighting: Training, techniques, & tactics. Stillwater, OK: Fire Protection Publications.

Hartin, E. (2007) Fire behavior indicators: Building expertise. Retrieved June 17, 2009 from www.firehouse.com.

Hartin, E. (2007) Reading the fire: Building factors. Retrieved June 17, 2009 from www.firehouse.com.

National Institute for Occupational Safety and Health (NIOSH). (2003) Death in the line of duty report F2001-23. Retrieved June 18, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200123.pdf

Bryner, N. & Kerber, S (2004) Simulation of the dynamics of a fire in the basement of a hardware store – New York, June 17, 2001 NISTR 7137. Retrieved June 18, 2009 from http://www.fire.nist.gov/bfrlpubs/fire06/PDF/f06006.pdf

United States Fire Administration (USFA) Firefighter fatalities in 2001. Retrieved June 18, 2009 from http://www.usfa.dhs.gov/downloads/pdf/publications/fa-237.pdf

Congratulations!

I would like to offer my congratulations to my two friends and colleagues Inspector John McDonough, ASFM of the New South Wales Fire Brigades and Acting Inspector Shan Raffel, CIFireE, EngTech, ASFM of Queensland Fire Rescue on receiving the Australian Fire Service Medal (AFSM) for distinguished service to their nation’s fire service. This is the second accolade for Shan in the last several months as he was recognized as a Companion of the Institution of Fire Engineers (IFE) for his work as national president and his tireless work for IFE Australia. Outstanding work gentlemen, honors well deserved!

Figure 1 ASFM Recpients Shan Raffel (left) and John McDonough (right)

B-SAHF! Master Your Craft

In Reading the Fire: B-SAHF, I introduced the B-SAHF (Building, Smoke, Air Track, Heat, and Flame) conceptual framework for reading the fire and have subsequently provided a series of video clips and photos to provide an opportunity to exercise your skill in reading the fire. While looking at video, photos (and actual incidents) may help build your knowledge and skill, different types of practice and knowledge building can also further your professional development.

Concept Maps

A concept map is a graphic tool for representing knowledge (Novak & Cañas, 2008). The map illustrates concepts and their relationships to one another (similar to an electrical circuit diagram or road map). Concept maps use a hierarchical form (similar to an organizational chart) with general concepts at the top and details further down. Mind maps are a similar tool often used in brainstorming that use a radial hierarchy with a tree-like hierarchy branching out from the center. I draw on both of these approaches in describing fire behavior indicators. A radial hierarchy is used as the foundation, but other relationships are illustrated and concepts can be interconnected in a variety of different ways.

A key step in improving your ability to read the fire is to think about what you should be looking for. Identifying key indicators and thinking about what they mean can be an important step in developing and improving your knowledge and skill. I find that this is an ongoing process as I continue to add to and refine my fire behavior indicators concept map. This map is not a fireground tool or a checklist of things to look for, but serves as a representation of my understanding and learning. While I am willing to share this map (Ed’s B-SAHF Map v5.2.1), it is more useful for you to build your own, representing your own understanding of these indicators and concepts.

Concept maps can be created using a pencil and paper, Post-It notes and an easel pad or white board, or using a computer with drawing software or a program specifically created for concept mapping. At one point or another, I have used each of these tools and find that they all have advantages and disadvantages. The tools you use are not as important as the mental process of collaborating with others and creating your map.

The Starting Point

Without getting bogged down an a long discussion of the educational and psychological foundations for concept mapping, it is important to understand that development of concept maps supports meaningful rather than rote learning. Rote learning often involves simple memorization. Meaningful learning requires three conditions (Ausubel, 1963).

• Concepts must be clear and presented with common language and examples connected to the learner’s prior knowledge.
• The learner must have relevant prior knowledge. Note that the learner does not require expertise, but needs sufficient knowledge to make sense of the concepts involved.
• Most importantly, the learner must choose to learn in a meaningful way.

Many firefighters struggle with creating mind maps (at first) because much of fire service training focuses on rote learning. However, I find that this challenge can easily be overcome if firefighters recognize the value of exploring the key fire behavior indicators and their relationships to one another.

Developing a concept map starts with a focus question that specifies the problem or issue that the map is intended to help resolve. The fire behavior indicators (FBI) concept map starts with the following focus question:

What building, smoke, air track, heat, and flame indicators
provide clues to current and potential fire behavior?

It is important to remember that a concept map is never finished. After you develop the first draft, it is always necessary to revise the map to increase clarity or add important concepts that you discover as work continues. For example, my FBI Concept Map is on Version 5.2.1, indicating five major revisions and 21 minor revisions or additions over seven years!

Knowledge Soup

The best concept maps are not developed in a vacuum. Collaboration with others can help us identify additional information and provides ideas that we may not have thought of on our own. For example, the current version of my FBI concept map started as my collaboration with Shan Raffel. However, it has evolved to include suggestions from hundreds of CFBT course participants.

Propositions or ideas developed by a group of learners may be thought of as ingredients in a kind of “knowledge soup” (Cañas, Ford, Hayes, Brennan, & Reichherzer, 1995, p. 4). The learners share the ingredients and each cook their own variation on the soup by constructing their own understanding. One way to approach this is to brainstorm key concepts and ideas before beginning the process of organizing the information and drawing the map.

Technology and Information Sharing

We have an advantage today that firefighters in previous generations did not have. Technology provides unparalleled opportunity for collaboration and learning. For example, this blog provides me with an opportunity to communicate and share information with firefighters around the world in a matter of minutes. In addition to my twice weekly blog posts, micro-blogging using the CFBT-US Twitter page provides a simple and easy method to rapidly share information on a daily (and in some cases hourly) basis.

Recently I have been reading a series of blog posts titled 31 Days to Build a Better Blog on Problogger. This stimulated my thinking about different ways to leverage technology to share information within the fire service and more particularly the compartment fire behavior community. Twitter may provide a simple means for collecting the ingredients needed for the knowledge soup necessary to develop and improve our respective fire behavior indicators concept maps.

This process could be started posting a question focused on one element of the FBI Concept map such as: What key building factors that impact on fire behavior can be used as indicators of current and predicted fire behavior? Readers can then respond (Tweet Back) with brief statements (no more than 140 characters) that identify the factors. All readers would then have access to this information when constructing the Building Indicators segment of their FBI Concept Map.

Another challenge is actually drawing the concept map (some of us are more graphically inclined or skilled than others). Bubble.us is a simple and easy to learn tool that provides a way to organize information as a concept map and share the work with others by e-mail, on the web, or embedded in a web page.

Figure 2. Bubbl.us Concept Map

Use of this software is free (you simply visit the bubbl.us web page, sign up and start creating your map. You can share your map with others to read or you can give them permission to edit the map. While I have not used this software extensively, it appears to be extremely easy to use and an excellent tool to simplify the process of drawing concept maps.

Where to from Here?

All very interesting, but how does this help us improve our ability to read the fire? Originally I had thought about using the “31 Days” concept to reading the fire. However, it will likely take a bit longer than that.

My next post will propose that we begin with an examination of building factors that influence fire behavior and which may serve as useful indicators in situational assessment. In the mean time, visit the CFBT-US Twitter page and respond to the question about building factors! Follow me for regular updates (you can also subscribe to an RSS Feed to receive information in a feed reader or via e-mail).

Each month I will move to the next element in the B-SAHF organizing scheme for fire behavior indicators until we have completed the entire FBI concept map. However, feel free to work ahead!

Ed Hartin, MS, EFO, MIFireE, CFO

References

Ausubel, D. (1963). The psychology of meaningful verbal learning. New York: Grune and Stratton.

Cañas,A., Ford, K., Hayes, P., Brennan, J., & Reichherzer,T. (1995) Knowledge construction and sharing in Quorum. Retrieved June 7, 2009 from http://www.ihmc.us/users/acanas/Publications/AIinEd/AIinEd.pdf

Novak. J. & Cañas, A. (2008). The theory underlying concept maps and how to construct and use them. Retrieved June 7, 2009 from http://cmap.ihmc.us/Publications/ResearchPapers/TheoryUnderlyingConceptMaps.pdf

Application of the B-SAHF (Building, Smoke, Air Track, Heat, & Flame) organizing scheme for critical fire behavior indicators to photographs or video of structure fires provides an excellent opportunity to develop your knowledge of fire behavior and skill in reading the fire.

Residential Fire

Shortly after 1730 hours on May 19, 2008, companies from the Baltimore City Fire Department were dispatched for a residential fire at 321 S Calhoun Street. Responding companies observed a large column of smoke from several blocks away.

Download and print the B-SAHF Worksheet. Watch the first 60 seconds of the video clip. Consider the information provided in this segment of the video clip. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators and then answer the following five standard questions?

1. What additional information would you like to have? How could you obtain it?
2. What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
3. What burning regime is the fire in (fuel controlled or ventilation controlled)?
4. What conditions would you expect to find inside this building?
5. How would you expect the fire to develop over the next two to three minutes?

1. Watch the next 60 seconds (first two minutes) of the video clip and consider the following questions:
2. What changes in fire behavior indicators have you observed in the second 60 seconds?

Watch the remainder of the video and see if your assessment matches actual incident conditions. Additional video of this incident can be viewed on the WBAL-TV { http://www.wbaltv.com/video/19514614/index.html ] web site.

Remember the Past

As mentioned in earlier posts, 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.

May 30, 1999
Firefighter Lewis Jefferson Matthews
Firefighter Anthony Sean Phillips, Sr.
District of Columbia Fire Department

District of Columbia Fire Department Firefighter Matthews and Firefighter Phillips were members of two different engine companies working on the first floor of a townhouse that was experiencing a fire. Both crews had entered the front door of the townhouse at street level. The fire was confined to the basement. The basement, at grade at the rear of the structure, was opened by a truck company and a small fire was observed. A company officer at the basement door requested permission to hit the fire but his request was denied by the incident commander since he knew that crews were in the building and he did not want to have an opposing hose stream situation. The fire grew rapidly and extended up the basement stairs into the living areas of the townhouse where Firefighter Matthews, Firefighter Phillips, and other firefighters were working. With the exception of Firefighter Matthews and Firefighter Phillips, all firefighters exited

the building after the progress of the fire made the living area of the townhouse untenable. On the exterior of the building, firefighters realized that Firefighter Matthews was not accounted for. Firefighters reentered the building and followed the sound of a PASS device. They removed the firefighter with the activated PASS to the exterior of the building. Once outside, firefighters realized that the firefighter who had been rescued was not Firefighter Matthews, but was, in fact, Firefighter Phillips. The search continued and Firefighter Matthews was discovered and removed approximately 4 minutes later. Firefighter Phillips’ PASS device was of the type that is automatically activated when the SCBA is activated and it worked properly. Firefighter Matthews’ PASS was a manually activated type and it was found in the “off” position. Both firefighters received immediate medical care on the scene and were transported rapidly to hospitals. Firefighter Phillips was pronounced dead upon arrival at the hospital and Firefighter Matthews died the following day, May 31, 1999. Firefighter Phillips died as the result of burns over 60 percent of his body surface area and his airway. Firefighter Matthews died as the result of burns over 90 percent of his body surface area and his airway. 2 other firefighters were injured fighting the fire. One (1) of these 2 firefighters, who suffered burns over 60 percent of his body surface area, survived and was released from the hospital in late August. At the time of his release, it was not clear if this firefighter would ever return to work. Additional information about this incident can be found in NIOSH Fire Fighter Fatality Investigation 99-F-21 and National Institute for Standards and Technology (NIST) report Simulation of the Dynamics of the Fire at 3146 Cherry Road NE, Washington D.C., May 30, 1999.

May 9, 2001
Firefighter Alberto Tirado
Passaic Fire Department, New Jersey

Firefighter Tirado and members of his department were dispatched to a report of a fire in an occupied three-story apartment building. The first-arriving engine company reported a working fire and Firefighter Tirado responded as the tiller driver of the first-arriving ladder company.

Firefighters on-scene received reports that children were trapped in the building. Firefighter Tirado and another firefighter from his company proceeded to the second floor of the building to conduct a search. A search of the second floor was conducted and all of the apartments on that floor were found to be clear. Firefighter Tirado and the other firefighter proceeded to the third floor to continue their search. On their way to the third floor, the team encountered heavy smoke and high heat. Both firefighters went back to the second-story landing. Firefighter Tirado’s partner told Firefighter Tirado to wait on the landing while he retrieved additional lighting from the apparatus.

A few minutes later, Firefighter Tirado called on the radio and said that he was trapped on the third floor. This transmission was not heard on the fireground and a second request for help was also not heard. He called a third time and reported that he was trapped on the third floor and needed help. Firefighter Tirado’s exit path had been blocked by fire, and he was unable to find his way out.

A defective throttle on the pumper supplying the initial attack line created water supply and pressure problems. Firefighters were unable to advance to the third floor to rescue Firefighter Tirado. The fire on the third floor grew to a point where it was impossible for firefighters to control it with handlines. An aerial master stream was used to darken down the fire and allow firefighters to access the third floor. After a number of attempts, Firefighter Tirado was discovered in a third-story bedroom.

The cause of death was listed as asphyxiation. Firefighter Tirado’s carboxyhemoglobin level was found to be 65%. The fire was caused by an unsupervised 12 year old girl that was attempting to light a stove. The children that were reported trapped were actually out of the building.

For additional information on this incident, refer to NIOSH Fire Fighter Fatality Investigation F2001-18.

Ed Hartin, MS, EFO, MIFireE, CFO

As discussed in previous posts, developing mastery of the craft of firefighting requires experience. However, it is unlikely that we will develop the base of knowledge required simply by responding to incidents. Case studies provide an effective means to build our knowledge base using incidents experienced by others.

Introduction

The deaths of Captain Matthew Burton and Engineer Scott Desmond in a residential fire were the result of a complex web of circumstances, actions, and events. This case study was developed using the Contra Costa County Fire Protection District Investigative Report and NIOSH Death in the Line of Duty Report 2007-28 and video taken by a Firefighter assigned to Quint 76 (Q76), the first alarm truck company. This case study focuses on the fire behavior and related tactical operations involved in this incident. However, there are a number of other lessons that may be learned from this incident and readers are encouraged to review both the fire district’s investigation and NIOSH report for additional information.

The Case

Early on the morning of July 21, 2007, Captain Matthew Burton and Engineer Scott Desmond were performing primary search of a single family dwelling in San Pablo, California. During their search, they were trapped by rapidly deteriorating conditions and died as a result of thermal injuries and smoke inhalation. Two civilian occupants also perished in the fire.

Figure 1. 149 Michele Drive-Alpha/Delta Corner

Note: Contra Costa Fire Protection District (Firefighter Q76) Photo, Investigation Report: Michele Drive Line of Duty Deaths. This photo illustrates conditions shortly after 0159 (Q76 time of arrival).

Building Information

The fire occurred in a 1,224 ft² (113.7 M2), one-story, wood frame dwelling with an attached garage at 149 Michele Drive in San Pablo (Contra Costa County), California. The house was originally built in 1953 and remodeled in 1991 with the addition of a pitched rain roof over the original (flat) roof.

This single story structure was of Type V, platform frame construction. The building was originally constructed with 4″ x 8″ (102 mm x 203 mm) beams supporting a flat roof with 2″ x 6″ (51 mm x 152 mm) tongue and groove planking with a built-up overlay consisting of several layers of tar and gravel. The pitched roof was constructed of 2″ x 8″ (51 mm x 203 mm) rafters covered with plywood and asphalt composite shingles. The ridge of the pitched roof was parallel to Side A. The gable ends on Sides B and D were constructed of plywood and fitted with a small gable vent.

Figure 2. Floor Plan-149 Michelle Drive

Note: This floor plan is based on data provided in the Contra Costa Fire Protection District Investigation Report and is not drawn to scale. The position of exterior doors and condition of windows as illustrated is based on the narrative or photographic evidence. Interior doors are shown as open as illustrated in the report. Fire service casualties are designated as follows: 1) Captain Burton, 2) Engineer Desmond.

All windows with the exception of the Living Room and Bedroom 1 (see Figure 2) were fitted with security bars (see Figure 3). The front door was the primary exit. In addition, an additional exit was provided from the kitchen through the garage to the exterior on Side D. The exterior door on Side D was fitted with a security grate.

Figure 3. View of Side C from the B/C Corner

Figure 4. Hallway and Bedroom 2

Note: Figures 3 & 4 adapted from Contra Costa Fire Protection District Photos (brightness and contrast adjusted to provide increased clarity).

Interior walls were gypsum board with wood veneer paneling on some of the walls (e.g., living room). All ceilings with the exception of the kitchen were exposed 2″ x 6″ (51 mm x 152 mm) tongue and groove planking (see Figure 4). The kitchen ceiling was covered with gypsum board. Ceiling height was 8′ (2.4 M).

Figure 5. Living Room

Note: Adapted from Contra Costa Fire Protection District Photos, Investigation Report: Michele Drive Line of Duty Deaths.

The Fire

Investigators determined that the fire likely originated on or near the east end of the bed in Bedroom 2 (see Figures 2 & 3). The likely source of ignition was improper discard of smoking materials. Developing into growth stage, the fire progressed from Bedroom 2 into the hallway (see Figures 2 & 4) leading to the living room, dining area, and kitchen (see Figures 2 & 5). It is likely that the door on Side A was closed at the time of ignition, but was opened by an occupant exiting some time after discovery of the fire.

Dispatch Information

Occupants discovered the fire and notified a private alarm company via two-way intercom at 0134. The alarm company notified the Contra Costa Regional Fire Communications Center of receipt of a fire alarm from 149 Michelle Drive at 0136 using the non-emergency telephone number. The alarm company did not indicate that they had talked to the resident who had reported a fire, but simply that they had received a fire alarm. The caller was placed on hold due to a higher priority 911 call. The dispatcher returned to the call from the alarm company at 0142 to obtain the address and callback information. Two attempts were made to call the incident location prior to dispatch of Engine 70 at 0144 to investigate the alarm. Contra Costa County Fire Protection District (CCCFPD) Engine 70 responded at 0145.

Shortly after Engine 70 responded, the communications center received a cell phone call from the female occupant at 149 Michelle Drive. This call was originally received by the California Highway Patrol and transferred to Contra Costa County Regional Fire Communications Center. The caller reported a residential fire and indicated that she had not been able to get her husband out of the building. Between the time that she spoke to the dispatcher and arrival of Engine 70, the female occupant reentered the building to attempt to rescue her husband (leaving the door on Side A open).

At 0146, the dispatcher upgraded the response to a residential fire and added two additional engines, a quint (as the truck company), and a battalion chief. Subsequent to the upgrade to a residential fire, additional 911 calls were received reporting a residential fire at 149 Michelle Drive.

Resources dispatched on the first alarm were as follows: Engine 70 (already responding on the initial dispatch for a residential alarm), Engine 69 (CCCFPD) as well as Rodeo-Hercules Fire Protection District Quint 76, and Battalion 7.  Richmond Fire Department Engine 68 was requested for automatic aid response through the Richmond Communications Center to fill out the first alarm assignment. Pinole Fire Department Engine 73 cleared a medical call a short distance away from the incident location and added themselves to the first alarm assignment. With the addition of Engine 73, the dispatcher canceled response of Engine 68 through Richmond Dispatch.

Note: Engine 73 was using an apparatus normally assigned at Station 74 which was marked with the designation Engine 74. This created some confusion during initial incident operations.

Weather Conditions

Conditions were clear, temperature was approximately 61^o F (16^o C), with a south to southeast (Side D to Side B) wind at between 2 and 6 mph (3.2 and 9.7 kph).

Conditions on Arrival

Shortly prior to arrival, Engine 70 reported “smoke showing a block out” and was advised by the dispatcher that the female occupant had been trying to get her husband out of the house and that it was uncertain if she had been successful. Engine 70 arrived at 0150, reported heavy smoke and fire from a single-story residential structure (flames and smoke were exiting from the open front door and large living room window on Side A), and established Command. Due to delays in the dispatch process, the time from the initial auomatic alarm until the arrival of E70 was approximately 16 minutes.(Refer to Contra Costa Fire Protection District, Investigation Report: Michele Drive Line of Duty Deaths for additional information regarding factors influencing the dispatch delay.

Questions

The following questions provide a basis for examining the first segment of this case study. You have an advantage that Captain Burton did not in that you are provided with a floor plan, photographs of Side C and the interior, and have knowledge of the eventual outcome. However, it is important that you place yourself in the situation encountered on arrival.

1. What stage(s) of fire and burning regime(s) were present in the building when E70 arrived? Consider potential differences in conditions in the living room, hallway, and bedrooms?
2. If you suspect that fire conditions in the living room were different than the hallway and bedrooms, why might this be the case? What evidence supports your position? What are your assumptions?
3. While limited information is available about the fire behavior indicators present during this incident, what Building, Smoke, Air Track, Heat, and Flame (B-SAHF) indictors did E70 observe when they arrived?
4. What B-SAHF indicators would you anticipate could have been observed on Sides B and C had this reconnaissance been conducted prior to making entry?
5. If you were faced with this situation, fire showing from the front door and window of a single family dwelling with persons reported, what actions would you take?
6. How do you think your selection of tactics would have influenced fire behavior and interior conditions?

Tactical Operations & Fire Behavior

My next post will examine tactical operations conducted by the first arriving companies and fire behavior encountered inside the building.

Ed Hartin, MS, EFO, MIFireE, CFO

References

Contra Costa County Fire Protection District.  (2008). Investigation Report: Michele Drive Line of Duty Deaths. Retrieved February 13, 2009 from http://www.cccfpd.org/press/documents/MICHELE%20LODD%20REPORT%207.17.08.pdf

National Institute for Occupational Safety and Health (2009).  Death in the Line of Duty Report 2007-28. Retrieved May 5, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200728.pdf.

Application of the B-SAHF (Building, Smoke, Air Track, Heat, & Flame) organizing scheme for critical fire behavior indicators to photographs or video of structure fires provides an excellent opportunity to develop your knowledge of fire behavior and skill in reading the fire.

This video clip was recommended by Captain Virgil Hall, Tualatin Valley Fire & Rescue. Virgil is stationed at Station 64 and is one of TVF&R’s CFBT Instructors.

Residential Fire

Download and print the B-SAHF Worksheet. Consider the information provided in the short video clip. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators and then answer the following five standard questions?

1. What additional information would you like to have? How could you obtain it?
2. What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
3. What burning regime is the fire in (fuel controlled or ventilation controlled)?
4. What conditions would you expect to find inside this building?
5. How would you expect the fire to develop over the next two to three minutes?

Review the video again, watch the indicators on Side A closely, and give some thought to the following questions posed by Captain Hall:

1. How did the smoke and flame indicators change?
2. What did this indicate?
3. Why did these changes occur (what were the influencing factors)?

Special thanks to Captain Hall for recommending this video clip. Please feel free to contribute to this process and share or recommend video clips or photographs that will help us develop our skill in reading the fire.

Remember the Past

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. The first narrative in this post is incomplete as this incident, resulting in the death of two members of the Houston Fire Department occured last Sunday. It is important for us to continue our efforts to understand and mitigate the complex and interrelated factors that result in firefighter fatalities occuring during structural firefighting operations.

April 12, 2009
Captain James Harlow
Firefighter Damion Hobbs
Houston Fire Department, Texas

Captain James Harlow and Firefighter Damion Hobbs of the Houston, Texas Fire Department lost their lives in the line of duty while conducting primary search in a single family dwelling on the morning of April 12, 2009. Preliminary information indicates that Captain Harlow and Firefighter Hobbs were trapped by rapid fire progress, possibly influenced by wind. The Houston Fire Department, Texas State Fire Marshal, and National Institute for Occupational Safety and Health (NIOSH) are all investigating this incident. More information will be posted as it becomes available.

April 11, 1994
Lieutenant Michael Mathis
Private William Bridges
Memphis Fire Department, Tennessee

On April 11, Lt. Michael Mathis and Private William Bridges of the Memphis (TN) Fire Department were killed when they became trapped and overcome by smoke during a fire on the ninth floor of a high rise building. Two civilians also died in the arson fire. Lt. Mathis became disoriented when he was caught in rapidly spreading fire conditions on the fire floor, burning him and causing his SCBA to malfunction. He found his way into a room on the ninth floor were he was later discovered by other fire crews with his SCBA air depleted. Private Bridges, aware that Lt. Mathis was unaccounted for after several unsuccessful attempts to contact him by radio, left a safe stairwell where he had been attempting to fix a problem with his own SCBA. Investigators believe Bridges was trying to locate Lt. Mathis. Bridges became entangled in fallen cable TV wiring within a few feet of the stairwell, and died of smoke inhalation after depleting his SCBA supply. A Memphis Fire Department investigation found many violations of standard operating procedures by companies on the scene, including crews taking the elevator to the fire floor, problems with the incident command system and coordination of companies, operating a ladder pipe with crews still on the fire floor, and a failure of personnel, including Lt. Mathis and Private Bridges, to activate their PASS devices.

April 16, 2007
Firefighter-Technician I Kyle Robert Wilson
Prince William County Department of Fire and Rescue, Virginia

Technician Wilson was assigned to Tower 512, a ladder company. Tower 512 was dispatched to a reported house fire at 0603 hours. The Prince William County area was under a high wind advisory as a nor’easter moved through the area. Sustained winds of 25 miles per hour with gusts up to 48 miles per hour were prevalent in the area at the time of the fire dispatch.

Initial arriving units reported heavy fire on the exterior of two sides of the single-family house, and crews suspected that the occupants were still inside the house sleeping because of the early morning hour. A search of the upstairs bedroom was conducted by Technician Wilson and his officer. A rapid and catastrophic change of fire and smoke conditions occurred in the interior of the house within minutes of Tower 512’s crew entering the structure. Technician Wilson became trapped and was unable to locate an immediate exit. “Mayday” radio transmissions of the life-threatening situation were made by crews and by Technician Wilson. Valiant and repeated rescue attempts to locate and remove Technician Wilson were made by the firefighting crews during extreme fire, heat, and smoke conditions. Firefighters were forced from the structure as the house began to collapse on them and fire conditions worsened. Technician Wilson succumbed to the fire and the cause of death was reported by the medical examiner to be thermal and inhalation injuries.

An extensive report on this incident is available from the Prince William Department of Fire and Rescue: Technician Kyle Wilson LODD Report.

For additional information regarding this incident, please refer to NIOSH Fire Fighter Fatality Investigation and Prevention Program Report F2007-12.

Ed Hartin, MS, EFO, MIFireE, CFO

Two incidents recently point to the hazards presented by explosions which may occur during firefighting operations.

Pittsburgh, PA

On March 25, 2009, firefighters in Pittsburgh, Pennsylvania were operating at a fire in a three-story apartment building of ordinary construction when an explosion occurred on Floor 2 while WPXI was videotaping fireground operations. Watch the video and see what you think?

• Did you observe any indicators of potential backdraft prior to the explosion?
• Do you think that this was a backdraft?
• What leads you to the conclusion that this was or was not a backdraft?
• If you do not think this was a backdraft, what might have been the cause of the explosion?

A news reporter quotes a chief officer, providing the following explanation: [Backdrafts] occur when a fire causes a buildup of pressure inside a building. When a firefighter enters a pressurized area, an influx of oxygen can cause the fire to explode. Note: comments reported in the press are not always an accurate representation of what was said.

While the comments reported are not completely inaccurate, they do not accurately describe the mechanism by which a backdraft occurs.

Cleveland, OH

On April 2, 2009, in Cleveland, Ohio an explosion occurred while firefighters were operating at a fire in a 2-1/2 story, wood frame dwelling. The fire, which had originated on the exterior of the structure, extended into the building and to the upper floors through void spaces in the balloon frame walls. According to news reports, the explosion occurred shortly after firefighters conducting primary search opened an attic door. The force of the explosion blew the two firefighters down the stairs to the second floor. Both firefighters received burns to the neck and face. News reports represented the phenomena involved in this event as a smoke explosion or backdraft.

• Based on the limited information provided in the news reports, which of these phenomena (backdraft or smoke explosion) do you think was most likely?
• What leads you to the conclusion as to which of these phenomena was most likely to have occurred?

A WKYC news report quoted a chief officer as stating “When they opened up the door to the attic that flow of oxygen allowed that fire to ignite, and it actually explodes.” Watch the video of this interview. This is a simple, but incomplete explanation of how a backdraft occurs. However, it does not explain the smoke explosion phenomena.

While smoke explosion and backdraft are often confused, there are fairly straightforward differences between these two extreme fire behavior phenomena. A smoke explosion involves ignition of pre-mixed fuel (smoke) and air that is within its flammable range and does not require mixing with air (increased ventilation) for ignition and deflagration. A backdraft on the other hand, requires a higher concentration of fuel that requires mixing with air (increased ventilation) in order for it to ignite and deflagration to occur. While the explanation is simple, it may be considerably more difficult to differentiate these two phenomena on the fireground as both involve explosive combustion.

While definitions are often ambiguous and the lines between various extreme fire behavior phenomena are a bit fuzzy, it is useful to examine even the limited information provided in news reports and give some thought to what might have happened. Are reported conditions consistent with the reported phenomena and what alternative theories might explain what happened?

Ed Hartin, MS, EFO, MIFIreE, CFO