Strategy and Tactics for Large Enclosed Structures - Part 4

Prior to conducting a cautious interior assessment, firefighters will need to examine concealed ceiling spaces for construction hazards and hidden fire which can cause a sudden collapse of the roof.


In the effort to reduce stress while increasing safety, control and effectiveness on the fireground, every responding company must clearly understand their role during an enclosed structure incident. Based on hard lessons learned, when executing the enclosed structure Standard Operating Guideline, a worst case scenario approach must be used from the outset. To achieve this, all supply lines and hand lines must be charged and staffed ready for use before the first engine company enters to assess the structure (See Figure 1).

At minimum, three fully bunkered back-up engine companies, on charged handlines, and one truck company serving as a RIT, all equipped with thermal imaging cameras (TICs) and portable radios, should be standing by at the initial point of entry. These companies must be prepared to immediately back up or rescue the first engine company should conditions rapidly deteriorate. The second truck company coordinates forcible entry and ventilation with command, making certain to avoid ventilation that may cause a flashover or backdraft. All back up companies will be monitoring radio transmissions between the first engine company officer and command and will team up to assist the first engine company in attacking the fire from the same direction or to assist as needed.

Avoiding Life Threatening Hazards
Since disoriented firefighters suffered fatal injuries following exposure to life threatening hazards including collapses of roofs and floors, prolonged zero visibility, flashovers and backdrafts, all firefighters must anticipate and look for these hazards during the operation. A safety strong point associated with use of the enclosed structure standard operating guideline is that it is programmed for firefighters to consider and avoid these hazards during an incident.

For instance, a 360-degree walk around is initially conducted not only to look for fire and enclosed windows or doors for use as secondary means of access and egress but also for signs of a basement and to note whether the basement is involved. A fire in a basement should be considered a potential life threatening hazard to every firefighter on the scene. To prevent firefighters from accidentally falling through a fire weakened floor and into an involved basement, everyone must be immediately alerted.

Prior to conducting a cautious interior assessment, firefighters will also examine concealed ceiling spaces for the presence of lightweight wooden or steel truss construction or unprotected steel and for hidden fire which can cause a sudden collapse of the roof. Moreover, a cautious interior assessment is a risk management process used to determine if it is safe enough for firefighters to advance to the seat of the fire from the initial point of entry or if it would be safer to approach the fire from a different side of the structure, closer to the seat of the fire. When this approach is used safety is enhanced because exposure to dangerous prolonged zero visibility conditions are minimized, reducing the possibility of a firefighter running out of air before exiting the structure. Similarly, the use of a "short interior attack" may also improve the safety and effectiveness of the rapid intervention team because shorter travel distances may reduce the overall difficulty and time associated in reaching and removing a downed firefighter.

The Potential for Flashover & Backdraft
In addition to protecting the lives of citizens and extinguishing the fire, firefighters are trained and expected to protect personal property. One common way this is accomplished during heavy smoke conditions is to wait until fire is actually visible before opening the nozzle and discharging water. This serves to prevent water damage and overall property loss. However, in certain circumstances, this traditional practice contradicts the priority of ensuring firefighter safety. Should a concern to prevent water damage mean that a firefighter may not take the initiative to protect him or her self against a life threatening event such as a flashover? No, since firefighters are instructed not to take unnecessary risks to save a structure, it follows that they should not risk their lives to prevent water damage.

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