Every response to an emergency incident requires the appropriate personnel and equipment. On structural incidents, the first alarm assignment consists of three engine companies,...

Every response to an emergency incident requires the appropriate personnel and equipment. On structural incidents, the first alarm assignment consists of three engine companies, one or two truck companies, an ambulance, the tactical safety officer and two battalion chiefs. There is also an additional engine that is dispatched once the incident is determined to be a working incident. In most cases, the initial alarm assignment will be adequate to safely manage the incident. However, some incidents require more personnel or equipment. In this instance, the Incident Commander, requests a second alarm assignment. This assignment may vary from one to two additional engines, an additional truck, possibly additional medic units, and even an additional battalion chief.

Additional resources may be needed for a number of reasons:

• The effects of extreme weather on crews battling a fire

• The size of the building 

• Multiple victims

• Multiple buildings involved

• A firefighter mayday

• The area that an incident covers

• Multiple critical factors

• Wind-driven fires

This list does not cover every reason for multiple alarms, but it gives you an idea of what could prompt the request. One of the first things that we were taught as rookies were the seven fundamental steps of firefighting, with step one being size-up and step two being call for help. A good size-up means drawing a mental picture of the incident for responding units, through a good verbal report of the first-arriving unit. A good size-up also determines the personnel and equipment needs, based on the critical factors that are determined. Critical factors might be victims to rescue, extinguishing the fire, controlling utilities, or a plethora of other things. 

Fires do not come at opportune times. Some fires occur at the same time that units are tied up on another emergency incident. In other words, the closest units to a fire are unavailable, causing units to have to respond from a distance. Fires might occur in the day, while you are not there, or at night, when you are sound asleep. Emergency communication operators have protocols for backfilling key stations during working incidents, which keeps busy areas covered, but leaves voids in areas where calls are less frequent. 

My shift had the opportunity to ride with Rescue 3 in New York City, a number of years ago. That particular night, companies got dispatched to what would be a city block on fire, causing multiple alarms. By the time that this incident was over, 250 firefighters had been dispatched to the scene. Major incidents, of whatever type, take a lot of resources, personnel and equipment, to mitigate. 2nd, 3rd…alarms are dispatched in the early stages of fire attack or rescue, causing units to have to travel longer distances under emergency conditions. You may not understand the information contained in this article, but be thankful that the fire service has all of this under control.