Avoiding the Residential Mindset
Knowing a building’s intended use is key to developing strategy and tactics.
NFPA Journal®, May/June 2009
While most firefighter deaths occur in residential fires, the probability of a firefighter being killed in a manufacturing occupancy is twice as great as it is in a residence, and nearly three times as great in stores and offices, places of public assembly, and vacant and special occupancies. Because most fires occur in one- and two-family dwellings, however, many firefighters have more experience fighting residential fires than any other kind. As a result, they tend to apply residential techniques to fires in other, larger occupancies. Unfortunately, the strategies and tactics that prove successful at small, residential properties are often ineffective, even dangerous, when applied at fires involving more complex, nonresidential occupancies.
In extremely large areas that are well involved in fire, for example, it will be impossible to extinguish the blaze using handheld lines. As rooms increase in size, the difficulty of extinguishing a fire increases, as well, due, in part, to larger rate-of-flow requirements. Most standard operating procedures for structural fires call for an initial pre-connect attack line and a back-up line of equal or greater size. Once a fire exceeds the capabilities of this standard attack, additional staffing, water supplies, and tactics are needed. In large, open areas, multiple 2½-inch fire streams may be needed, thus exposing firefighters and civilians to a hostile fire environment over a larger area for a longer period of time.
Over time, as a fire increases in size and intensity, the likelihood of building collapse also grows. In most residential properties, rooms are of limited size, and the walls tend to partially support a collapsed roof. Roof failure over a large open area presents a much greater hazard to firefighters working below.
Escape routes are also closer and easier to find in most single-family homes than they are in larger buildings. While depleting the SCBA air supply or an SCBA failure often results in survivable smoke inhalation in a residential fire, the loss of air supply in a larger, more complex building is more likely to be fatal because more time is needed to escape, and there is a higher probability of disorientation. Rapid intervention crews (RICs) generally need more time to find and extract firefighters in large buildings, particularly buildings with large open areas, than they do in a single-family house.
In addition, large-area buildings, such as places of assembly and mercantile occupancies, may have high occupant densities during business hours. These buildings are particularly dangerous for firefighters, who accept greater risk to save a human life than they would if only property were at stake. Compare the risks firefighters typically encounter in a single-family house to those the Charleston, South Carolina, Fire Department faced at the 2007 fire at the Sofa Super Store, for instance. The store was still occupied by employees when the fire, which killed nine firefighters, began.
The incident commander facing a fire in a large, complex building without a pre-incident plan is at a distinct disadvantage. A fire department confronting a fire in such a structure will need additional staffing to augment the RIC and to fight the fire if an offensive attack strategy is employed. Firefighters and company officers should be aware of the increased hazards when fighting fires in larger buildings and take extra precautions. It is important to avoid a single-family residential mindset.
This column is adapted from the author's book StructuralFireFighting, available online or (800) 344-3555.