Extinguishing a Fire in a Bank Vault

OUR SUNDAY MORNING ROUtine was suddenly disrupted by the station alert: “Report of smoke from the bank.” A still alarm of one engine, one truck, one ambulance, and one mutual-aid automatic response engine was dispatched. En route, the 911 dispatcher advised that the caller was at the location and reported smoke from the night deposit box. On arrival, nothing was showing. We walked up to a lady who was signaling us. As we approached, there was a faint smell of smoke. When we opened the door for the night depository, a light smoke wafted out.

Many night depositories are designed so that a flat envelope can be inserted into a narrow opening in the box (photo 1). Business customers requiring larger bags for deposits usually are issued a security key, which allows the deposit box to open fully (photo 2). Once a deposit bag is placed into the drop box and the door is closed, the mechanism activates. Only then is the deposit dropped into the bank’s secured vault (photo 3). The problem is that at no time is there direct access from the outside into the secured area of the vault. Dispatch notified a key holder for the bank, who was on his way. Unfortunately, unlocking the vault necessitates the actions of two people. We did not know how long it would take to open the vault. Knowing that something was burning, we had to decide on a course of action.

1. Photos courtesy of author.







At a previous similar incident to which I responded, the vault was on a time lock; no one could open it until the next morning. In that incident, we placed wet towels into the deposit box and cycled the mechanism in hopes that the fire would be smothered. The next morning when the vault was opened, it was determined that the papers in the depository had smoldered throughout the night.

We thought we would use a dry powder on this fire. All the extinguishers carried on the first-in engine were stored pressure. Since there was no way to shoot the agent directly into the vault area, we grabbed a Purple K extinguisher from the mutual-response engine. We twisted off the top (photo 4), since the extinguisher isn’t pressurized until it’s charged by piercing a separate CO2 cartridge. With the aid of a shovel, we were able to pour the Purple K directly into the area normally used to hold the deposit bags (photo 5). Once we had it filled, we closed the door and let the mechanism cycle through dropping the extinguishing agent right on top of what we believed to be the area of the fire.




In the meantime, a bank key holder arrived and was able to get access to the basement where the vault was located. We were still waiting for the second bank representative who would allow us to access the inside of the vault.

We no longer smelled smoke, and no smoke was visible. However, there was a fine haze of the agent outside the vault in the basement. A short while later, the other bank representative arrived and was able to open the vault (photo 6).


It was determined that the agent had extinguished the fire and that the cause of the fire was the placing of ignited ordinary combustibles in the deposit box. Security cameras were able to determine who was responsible for the fire; the police were able to make an arrest. After some cleanup, most of the deposits were salvaged.


It would be unlikely to have enough ordinary combustibles inside the depository holding area to enable a fire to spread into the structure. Although many bank buildings have sprinkler systems, you may want to look a little closer at your plan reviews to determine if the night deposit box vault should be covered by a smoke detection system.

DWAYNE ERIKSEN, a member of the fire service since 1977, is a member of the North Riverside (IL) Fire Department, where he is a training instructor. His certifications include fire officer II, trench rescue, confined space, high angle, road rescue, fire apparatus engineer, paramedic, and fire investigator.

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