Commercial Building Fires: When To Go Defensive


No decision made at a working structure fire is more basic or advanced than “offensive” or “defensive.” No other decisions can or need be made before the incident commander (IC) determines the strategy that will be employed. You might think the decision to “go” or “not go” would be simple and straightforward, but nothing could be further from the truth. No other decision made during the course of an incident places firefighters in immediate danger or calculated safety more than the offensive or defensive decision. Nowhere else is the potential for immediate catastrophic failure and subsequent multiple injuries or deaths more present than at a commercial building fire—a fire in an occupancy that is not classified as single or multifamily residential.

(1) A change in strategy must occur early enough to allow for safe and orderly withdrawal to defensive positions prior to the catastrophic failure of the building. These firefighters have withdrawn, and a “defensive” operation has been initiated. (Photo by Glen Ellman.)

With such dire consequences riding on this decision, you would think there would be no shortage of literature, training materials, or training programs that address the definitive criteria ICs should evaluate when making this strategic decision. Unfortunately, this is not the case. Even fire service literature authored by some of the most respected leaders in the industry stop short of specifically identifying critical factors that should indicate when to use an offensive or a defensive strategy.

Contrast this shortage of information with the emergency medical protocols that guide our decision-making process when confronted with situations of full cardiac arrest. The University of Texas Southwest Protocols for Therapy1 very clearly defines the criteria that paramedics should look for when determining whether or not to initiate cardiopulmonary resuscitation on people found in full arrest. Dependent lividity, rigor mortis, decomposition, decapitation, incineration, head or chest injury visibly incompatible with life, and the presence of “Do Not Resuscitate” orders are all acceptable reasons for not initiating life-saving measures. A list of definitive reasons for which paramedics can “write off” a life exists; however, a list of reasons firefighters can use to “write off” a structure has yet to be developed.


Despite increased awareness and training, there has been no significant decrease in the number of line-of-duty deaths (LODD) at commercial building fires in the United States in the past 20 years. Without a policy or guideline, company officers and battalion chiefs, as well as others in similar positions throughout the country, are left to make split-second decisions with unparalleled consequences. If the fire service’s goal of reducing the number of LODDs of firefighters in the United States is ever to be realized, significant changes must be made.

Numerous incidents over the past 20 years suggest the need to establish definitive criteria for strategic decision making at commercial building fires.

  • On July 1, 1988, five firefighters were killed at Hackensack (NJ) Ford. The men died when the bowstring-truss roof of an auto dealership in which they were working collapsed on them.
  • On December 3, 1999, an accidental fire claimed the lives of six Worcester, Massachusetts, firefighters. The men became disoriented while operating in a vacant six-story cold-storage warehouse.
  • On February 14, 2000, an early morning fire in a McDonald’s restaurant claimed the lives of two Houston, Texas, firefighters. They, too, were killed when the roof of the restaurant collapsed on them.
  • On June 18, 2007, nine Charleston, South Carolina, firefighters died while fighting a fire in the Sofa Super Store. The men were operating inside the building when the steel-bar joist roof suddenly collapsed on them.

In each of the above incidents, the first-arriving company officer or the IC initiated an offensive strategy. Unfortunately, in each of these instances, the decision to change to a defensive strategy never came up or came too late to save these firefighters’ lives. These incidents are only a snapshot of what has been an ongoing trend in the U.S. fire service over the past 20-plus years. The trend is to commit firefighters to an offensive strategy at commercial building fires with little to no guidelines or training on how to recognize and interpret critical factors that would dictate the need for a change in strategy. Change must occur early enough to allow for safe and orderly withdrawal to defensive positions prior to the catastrophic failure of the building.

Numerous books, reports, and statistics point to the need for change in our response to commercial building fires. According to the National Fire Protection Association (NFPA) report on Firefighter Fatalities 2007,2 102 firefighters were killed in the line of duty. Even though more deaths occur at residential fires than at any other type of occupancy, commercial buildings continue to pose the greatest risk. Despite the considerably lower number of responses to commercial buildings, 6.4 firefighter deaths occurred at these types of buildings for each 100,000 responses, compared to 3.7 deaths for each 100,000 responses to residential fires. (2) The report also notes that the highest death rates over the five-year period from 2002 to 2006 occurred in stores and offices.

Heightened awareness, increased training requirements, and active efforts by fire service leaders to reduce the annual number of LODDs of firefighters in the United States has failed to provide a consistent appreciable decrease over the past 30 years. According to NFPA statistics, the number of LODDs (excluding the deaths at the World Trade Center in 2001) has ranged from a high of 173 in 1978 to as low as 75 in 1992 but has consistently exceeded 100 over the 30-year time frame from 1977 to 2007. (2) This fact is particularly disturbing considering there has been more than a 16-percent decrease in the number of nonresidential structure fires in the United States between 1999 and 2007.3 An estimated 530,000 structure fires were reported to public fire departments in 2007. This represents a relatively steady decrease in structure fires from a high of 1.098 million in 1977.4

Many theories reveal how fire officers make decisions on the fireground—from basic situational awareness and risk vs. benefit models to more complex studies of intellectual recall. The Firefighter’s Handbook, 3rd edition,5 defines strategic goals as “the overall plan developed and used to control an incident.” Basic fireground strategies can be divided into offensive and defensive. The National Fire Protection Handbook, 19th edition (2003), calls the offensive-defensive decision “the most critical factor in the risk-benefit analysis.”6 An offensive strategy occurs when firefighters advance attack lines inside a building to attack a fire at its base. The method hopes to place the firefighters in close enough proximity to the seat of the fire to direct the extinguishing agent, most commonly water, directly on the burning material. The justification, or advantage, of an offensive strategy is an attempt to contain the fire to as small an area as possible and minimize the damage.

A downside to this strategy is that firefighters must enter the structure, subjecting them to the products of combustion and the possibility of being trapped by a catastrophic collapse of the building.

In contrast, a defensive strategy is most often employed at incidents where it is believed that the fire has escalated beyond the control of an offensive attack or “where the level of risk to firefighters conducting an interior attack would be unacceptable.”7 A defensive strategy calls for the use of master streams and large-diameter handlines to direct water on or into the building through natural or manmade openings in the structure while keeping firefighters in exterior positions that are deemed relatively safe (photo 2). (7)

(2) Firefighters are operating master streams in a defensive strategy. (Photos by Billy Bennett.)
(3) Large-diameter handlines are employed on this strip shopping center during a defensive operation that has escalated beyond the control of an offensive attack.


What factors should influence a fireground officer’s perception of the level of risk? Despite the presence of many books, videos, and classes on strategic decision making, there has yet to be developed a list of agreed-on criteria that would help company officers or ICs arrive at a common and consistent level of risk for the same or a similar incident. What critical factors should be considered when choosing one strategy over another?

Some texts and articles contained limited information on such a list. Phoenix (AZ) Fire Department Chief (Ret.) Alan Brunacini addressed the issue of criteria ICs should use when making strategic decisions. According to Brunacini, our basis for what he refers to as “operational incident strategy management” evolved from military terminology that has been adapted for use in the fire service.8 He refers to numerous factors the IC should consider when determining whether the correct operational mode would be an offensive or a defensive strategy. In a section titled “Identifying the Strategic Mode,” Brunacini lists “an array of standard critical incident factors and their related characteristics.” They include “the fire’s extent and location, any savable occupants, fire effect, savable property, entry and tenability, ventilation profile, special hazards, local violence, terrorism, and resources.” Other texts, such as Firefighting Strategy and Tactics,9 indicate that the IC’s offensive vs. defensive decision should be based on answers to the following questions:

  • How much fire department attack force do I have?
  • How much fire must these forces attack?
  • Are there lives endangered that can be safely rescued? Carter explains: “Where there is more fire than attack force, the choice would probably be defensive in nature.” (9) He does not, however, specify how the IC should make that determination.

Pulling his crews out of a burning building and going defensive is one of the most courageous decisions an IC can make.10 Firefighters consider pulling out of, or being ordered out of, a burning building “downright cowardly.” The IC should monitor four main categories of conditions during an incident—building construction, equipment conditions, staffing issues, and fireground conditions—and should continually monitor the building for safety problems such as structural degradation or evidence of impending collapse. Also, it is important to interpret changes (or the lack thereof) to determine the progress crews are making in controlling the fire. (10)

(4) It can take in excess of 800 or 900 gallons per minute of water to knock down a large fire in a store; it could take much more than that depending on the percentage of the building involved. (Photo by Billy Bennett.)

(5) It is critically important that the incident commander accurately estimate the amount of time the fire has been burning, evaluate the building construction, and read the smoke and use these assessments as a gauge for deciding what has already been lost vs. what is still savable. (Photo by John Bellingham.)

Other items related to building conditions considered critical are means of ingress and egress, lack of progress by the ventilation crew, and fire spreading unchecked over the heads of interior crews. Apparatus malfunctions, insufficient staffing, and a lack of progress by the initial attack crews are also justifications for changing to a defensive strategy. (10) The last and most obvious factor is that “the incident may simply be too large for handlines and interior firefighting.” (10)

Brunacini expands on some of the factors he addresses in Fire Command in the article “Timeless Tactical Truths.”11 Accurately estimating the time the fire has been burning and using that assessment as a gauge for deciding what is already lost vs. what is still savable are of critical importance to the IC. (11) The accuracy of this assessment will depend on the officer’s experience and training. Those same two characteristics, experience and training, will be crucial in evaluating what progress, if any, is being made. According to Brunacini, evaluating the effect of the actions being taken should be self-evident: “It does not take long to know if what we are doing is working.” (11, 208). If we determine it is not working, it is up to the IC to either direct more resources to reinforce the current positions or make the decision to change to a different plan altogether.

Another author who attempts to address some of the critical factors is Fire Department of New York Deputy Assistant Chief (Ret.) John Norman. According to Norman,12 fire loads are typically higher in commercial buildings; hence, there is a need for increased fire flows to combat fires within these types of structures. The increased fire load is usually the result of materials stored within the building rather than the materials from which the building is constructed. Another point Norman makes, which must be considered a critical decision factor, is that it can take in excess of 800 or 900 gallons per minute (gpm) of water to knock down a large fire in a store. (12, 353) Among the most important factors Norman addresses are lightweight truss-roof systems and plywood I-beams. He compares making an offensive attack on a well-developed fire in a building where these types of construction are present to “playing Russian Roulette with three bullets in the cylinder.” To expand on or explain Norman’s assertion that it can take nearly 1,000 gpm of water to extinguish a well-developed fire in a commercial building, one must examine the way fire flows are calculated. According to the Fire Chief’s Handbook13 the National Fire Academy’s (NFA’s) formula for determining the Required Fire Flow is

Required Flow in gpm = L × W3 × Number of Floors Involved
Where: GPM = Gallons per minute,
Where: L = Length,
And W = Width of the structure in feet.

The Required Fire Flow is for a fully involved structure. If only a portion of the structure is involved, the amount should be reduced accordingly. Typically, this reduction is calculated by estimating the percent of the structure involved such as 10 percent, 25 percent, or 50 percent. (13) The 19th ed. of the NFPA’s Fire Protection Handbook indicates that “the essential question to be answered is, how many gpm are required to extinguish a given fire with properly placed hoselines?” (6, 7-337) The required fire flow calculation is considered so important in this case because it must be known to determine how many firefighters will be needed to operate the necessary number and size of hoselines to achieve the required flow. (6)

Applying this formula to two different, well-known businesses illustrates the point that, indeed, Required Fire Flow should be considered a critical factor for strategic decision making.

Example 1: a McDonald’s restaurant. It measures 70 feet wide × 120 feet long. Required Fire Flow =   or 2,800 gpm for 100 percent involvement; 1,400 gpm for 50 percent involvement; 700 gpm for 25 percent involvement; and 280 gpm for just 10 percent involvement.

Example 2: a Wal-Mart store. The store measures 400 feet long × 620 feet wide. Required Fire Flow =   or 82,666 gpm for 100 percent involvement; 41,333 for 50 percent involvement; 20,666 for 25 percent involvement; and 8,266 gpm for 10 percent involvement. The NFA formula provides a 2.3 safety factor, but that has to be accounted for to place attack and backup lines. These are basic requirements for interior fire attack mandated in NFPA 1500, Standard on Fire Department Occupational Safety and Health Program, 2007 edition. 

Be aware that most research on the NFA’s Fire Flow Formula agrees that it is not effective for defensive operations and the calculations tend to be inaccurate above 1,000 gpm.

As we stated at the beginning of this article, the decision to operate in an “offensive” or “defensive” mode places firefighters in a position of immediate danger or calculated safety. The ability to correctly identify problems and develop an incident action plan to address problems is what determines the success or failure of the initial IC’s strategy. Choosing the correct mode of attack (offensive or defensive), apparatus placement, line selection, line placement, and incident organization all play a very important role in determining if the incident will have a favorable outcome or not. ICs have to implement a risk-management plan at all incidents. Every fire department has limitations. In some situations, the availability of personnel may define the limitations; in others, it may be the reflex time associated with the arrival of mutual-aid companies; in still other departments, the size and magnitude of the incident will be the determining factors.14


We offer the following criteria for the IC’s initiating a defensive strategy or switching from an offensive operation to a defensive one.

Use OFFENSIVE strategy = We are willing to get someone killed for what remains to be saved, IF

  • There is a life safety issue (savable victims).
  • The percentage of the building on fire. Consider the percentage of the building in relationship to the total square footage: 10 percent of a 100,000-square-foot building is worse than 25 percent of a 5,000-square-foot building. The question is, can the first-alarm companies deliver the gpm to combat the volume of fire they have based on this percentage?
  • Using the Fire Flow Formula (L × W ÷ 3 = gpm) as your guide,
    —You can sustain the needed fire flow.
    —You have sufficient personnel to direct the large-diameter hose streams necessary to achieve the needed fire flow.
    —It is practical to believe you can achieve the fire flow in the area needed in a short enough time to make a difference in the outcome (reflex time).
    —The needed fire flow is included in the prefire plan.
  • The personnel on scene are adequate to safely conduct the operation:
  • —two-in/two-out.
    —backup line.
    —rapid intervention.

Other Determining Factors 

  • Do you know the building’s occupancy type, building contents, and location of the fire inside the building?
    —Storage: What is stored in that area of the building, dog food or dynamite?
    —Industrial process: What process is conducted in that area of the building, general product assembly or metal plating using combustible or hazardous materials?
    —Manufacturing: Are they manufacturing cardboard boxes or bombs?

Continuously monitor for signs that you should switch to a DEFENSIVE strategy, including the following:

  • Read the smoke conditions, track the time the fire has been burning, and note the size and intensity of the fire and the effect the fire is having on the building.
  • Identify the type of building construction. Different types of construction offer different time frames before failure or collapse:
    —Dimensional lumber construction vs. heavy timber.
    —Heavy timber vs. steel bar joist.
    —Steel bar joist vs. lightweight wood-truss systems.
  • Answer this question honestly: Is the building already lost?

Use DEFENSIVE strategy = There is nothing left to save that is worth the risk of getting a firefighter killed, IF

  • The crews have been operating inside the building for longer than 10 minutes with no appreciable change in conditions.
  • The building is dilapidated, abandoned, or vacant.
  • The fire is burning through the roof of a commercial building.
  • The attack hoselines must be advanced more than 150 feet inside the building from the closest entrance to the seat of the fire.
  • The fire has overrun or is beyond the capability of properly functioning fixed fire protection systems (sprinklers).
  • The lightweight truss (wood or metal) is involved in fire and there is no change in conditions with the first attack line in operation.
  • You cannot communicate with your personnel.
  • Building collapse indicators are present: cracks, a sagging roof, smoke showing through the seams in walls, leaning walls.

We have to change the mindset of using residential tactics at commercial building fires. This mindset sets us up for failure and needlessly risks the most important resource of our fire departments—our people. Many times we get lucky, and this luck only builds bad habits. We should pose these three questions to ourselves: (1) Why are we in the building? (2) What is the best possible outcome? (3) Does it still make sense for our personnel to be in the building?


1. Pepe, P. (2007, January 1). UTSW/BioTel EMS system guidelines for therapy. Retrieved November 29, 2008, from Biotel:

2. Fahy, R, LeBlanc, J, and Molis, J, “Firefighter fatalities 2007” NFPA Journal; July 2008, 74-92.

3. National Fire Protection Association. Non-residential structures. (2007). Retrieved February 21, 2009, from U.S. Fire Administration.

4. Kartner Jr, M. Fire Loss in the United States 2007. Quincy, Mass: National Fire Protection Association, 2008.

5. Main, L. (2008). Firefighter’s Handbook, 3rd ed. Clifton Park, NY: Delmar.

6. Cote, A. (2003). Fire Protection Handbook, 19th ed., Vol 1. Quincy, MA: National Fire Protection Association, Inc.

7. McIsaac, J; Rogers, C; and Stoppa, S. Fundamentals of Firefighter Skills. Sandbury, Mass: Jones and Bartlett Publishers, 2008.

8. Brunacini, A. Fire Command, 2nd ed. Phoenix, Ariz: Heritage Publishers, Inc., 2002.

9. Carter, H. (1998). Firefighting strategy and tactics. Stillwater, OK: Fire Protection Publications.

10. Jakubowksi, G, “Get out.” Fire Rescue; July 2008, 40-43.

11. Brunacini, A. (2008 May). Timeless tactical truths. Fire Engineering, 208.

12. Norman, J. Fire Officer’s Handbook of Tactics, 2nd ed. Saddle Brook, NJ: PennWell Corporation, 1998.

13. Bachtler, J and Brennan, T. The Fire Chief’s Handbook, 5th. ed.Saddle Brook, NJ.: PennWell Corporation, 1995.

14. Grant, Stuart, “First Alarm Considerations,” Fire Engineering, July 2005.

The authors will present the workshop “Strategy and Tactics at Commercial Fires” at FDIC 2011 in Indianapolis, Indiana, on Monday, March 21, 1:00 p.m.-5:00 p.m.

STUART GRANT, CFO, a 32-year veteran of the fire service, is a battalion chief with Dallas (TX) Fire Rescue. He is a certified master firefighter and fire instructor with the Texas Commission on Fire Protection. He has served in many capacities within the department, including academy commander, hazmat officer, paramedic, and rope rescue member. He is a Task Force leader for the Dallas Regional USAR team and the state’s second USAR TX-TF2 team. He has been a H.O.T. instructor and speaker at FDIC and instructs at Collin College in McKinney, Texas, and at the Texas A&M University Municipal Fire School. He has two associate degrees and a bachelor’s degree in fire administration. He has also been recognized by the Center of Public Service Excellence as a Chief Fire Officer.

LES STEPHENS, a 19-year veteran of the fire service, is chief of the San Marcos (TX) Fire Department. He is a certified master firefighter and an instructor with the Texas Commission on Fire Protection. In addition to serving two years as a training officer in the Garland (TX) Fire Department’s Training Division, he was also an instructor with Collin College’s fire science program, Dallas Fire Rescue’s recruit academy, Texas A&M’s municipal fire school, and FDIC. He has an associate degree in fire protection from Tarrant County College and is enrolled in the National Fire Academy’s Executive Fire Officer program. 

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