The arrival of firefighting forces at a well-involved commercial structure fire is a low-frequency, high-risk operation for many departments for several reasons, including but not limited to:
- Officers and firefighters do not have much experience managing such incidents.
- Departmental staffing, even when supplemented by mutual-aid companies, is inadequate.
- The water supply infrastructure may not be capable of delivering adequate water to the scene.
- Changes in a building's occupancy, fuel load and fuel arrangement occur over time.
Frequently, the incident commander determines that defensive is the appropriate mode of operations based upon their size-up of the building, the fire, and their available resources. This decision also comes with some unique challenges.
- Personnel lack experience in the safe, effective and efficient implementation of a defensive strategy.
- Lack of sufficient types of apparatus and equipment may hinder the ability to deliver sufficient fire flows from the necessary attack points.
- Large volumes of water flow create a significant run-off of contaminated water from the structure that must be managed.
Watch the following video that involved a truck and trailer repair facility. Use the discussion points to review this incident with your personnel to increase their knowledge of such incidents.
- What are the risk to firefighters and the civilian population presented by the smoke from this fire?
- How would you manage those risks?
- What are the hazard presented by the contaminated water run-off resulting from the large volume of water being delivered to this fire?
- How would you manage that risk?
- What are the key operational and safety aspects of conducting a safe, effective and efficient defensive operation for this fire?
What are the pros and cons of: (1) letting the fire burn to reduce the contaminated water run-off hazard — thereby reducing the risk to the environment or public sewer system, or (2) extinguishing the fire to reduce the production of the contaminated smoke — thereby reducing the downwind population to the hazards of the smoke?