The alarm system is used by the New York City fire department and many others across the country to signal how many firefighters and vehicles are needed, either to battle a blaze or to relieve workers throughout the fight.

In New York, the first alarm, usually called “all hands,” requires about 12 units, or 60 firefighters.

A five-alarm fire demands roughly 44 units, or 200 firefighters. And a 10-alarm fire usually means about 70 units, or 350 firefighters, are dispatched. There are a variety of types of units, including ladder companies and engine companies.

A look at the FDNY’s alarm system

The alarm system is used by the New York City fire department and many others across the country to signal how many firefighters and vehicles are needed, either to battle a blaze or to relieve workers throughout the fight.

In New York, the first alarm, usually called “all hands,” requires about 12 units, or 60 firefighters.

A five-alarm fire demands roughly 44 units, or 200 firefighters. And a 10-alarm fire usually means about 70 units, or 350 firefighters, are dispatched. There are a variety of types of units, including ladder companies and engine companies.

During the 2001 attacks on the World Trade Center, the devastation was so great that the fire department stopped counting alarms, according to historian John Mulligan.

Tuesday’s fire at a complex of warehouses in Brooklyn was battled by 80 units and more than 400 firefighters.

It was the city’s largest blaze excluding the trade center disaster since 1995, when a 19-alarm fire gripped Brooklyn’s St. George Hotel, requiring more than 500 firefighters.

Though the alarm system provides guidelines, fire officials say there’s no strict formula for how many firefighters respond to a blaze and that all numbers are estimates.

There are more than 11,400 uniformed firefighters and fire officers in the five boroughs.

4 Comments

  • Enlightened

    Webby,
    These informative articles are a fascinating addition to the news.

    Keep it up.

  • Mendel Fitzhume

    We can sleep well at night knowing that this alarm system is in place. The good men who dispatch our firemen are right nearby in their historic office near the Botanical Gardens. They do an admirable job!

  • Frank Raffa

    There is no exact formula for counting the number of fire fighters at the scene because each unit has a different staffing level. Ladders and rescues have 5 FFs and an office. Engines can have 4 or 5 FFs and an officer.

    We determine the alarm by counting the number of engines and dividing by 4. You can see more about how we work here: http://www.FDNewYork.com/aa