Apr 2023

4 Critical Loss Lessons from Large Warehouse Fires

With the increase in large catastrophic, sprinklered warehouse fires in the last several years, one must wonder if any loss lessons have resulted in better practice. Since the 1982 K-Mart fire, several large sprinkler protected warehouses over 1 million ft2 in area resulted in a loss due to fire.

Recent statistics (1980 – 2020) from NFPA research reveal that fires in warehouse properties have declined substantially in number since 1980; however, property damage monetary losses have increased over the same period due to very large fires causing significant spikes on annual totals.

Here are 4 of the most critical loss lessons:

1. Fire protection design

Usually, protection is adequately designed to the highest hazard. However, with the boom in speculative warehouse construction and the tenant not known, the commodity design is generally up to Class IV/cartoned plastics. This may not be adequate for future occupancy if exposed plastics or more hazardous commodities are stored.

2. Water supplies

Again, the volume, pressure and duration designs have generally been adequate. However, property insurers and AHJs now accept one fire pump for these very large warehouses. There is usually no requirement for backup supplies (second fire pump – one with diesel drive). While statistics show that a properly inspected, tested and maintained (ITM) fire pump is very reliable, the unit must stay in service to work properly in the event of a fire.

3. Fire service operations

This consists of two, interrelated actions:

a. Keep fire protection in service.

Sprinkler valves and fire pumps need to stay in service for the full fire event. Protection must stay in service until the fire is completely extinguished.

b. Sprinkler designs are based upon automatic venting not being present.

Fire service venting operations should only begin after the full suppression of the fire. Premature protection shut down and early ventilation efforts have lead to a loss of initial fire control efforts. Rekindling fire events with fire protection out of service have resulted in complete loss of large warehouses. Unintentional ventilation and subsequent rekindle can also be unintentional, such as through open dock doors.

Resources for the fire service and occupant include FM Global training, Fighting Fire in Sprinklered Buildings and NFPA 13E, Recommended Practices for Fire Department Operations in Properties Protected by Sprinkler and Standpipe Systems.

It is essential that a preplan with periodic review is conducted with the fire service. Ideally, the property insurer and servicing risk engineer should attend these sessions.

Above: Walmart Distribution Fire, March 2022

4. Fire Protection Impairment Procedures

Fire protection equipment ITM is necessary on frequencies established in NFPA 25, Standard for Inspection, Testing and Maintenance of Water-Based Fire Protection Systems. Often, proper impairment procedures become overlooked. Management and insurance/risk service personnel must periodically audit the program to ensure there are no gaps that would allow a prolonged fire protection impairment to exist.

Risk Logic can recommend fire protection design criteria, help develop preplans with the fire service and audit all property loss control programs at your facility. Please contact us to schedule a property survey by one of our engineering specialists.