what is a 3 alarm fire

In the United States and Canada, the term "alarm" is used to classify the seriousness of fires, indicating the level of response by local authorities. A three-alarm fire means that triple the amount of firefighters, trucks, and equipment will be dispatched to the scene of the fire. The designation of a three-alarm fire can vary by area, but it generally means that the fire is severe and difficult to contain. The number of alarms correlates to how severe and complex a fire or other incident is to mitigate. The number of resources, including fire engines, trucks, chiefs, specialty units, and personnel, needed to manage an emergency incident increases with each additional alarm. For example, a first alarm usually dispatches two to three fire engines, one to two fire trucks, one chief officer, and one light/air refill unit, while each additional alarm will send one more unit of each type. A three-alarm fire is a significant deployment of resources, and the department may also send out a media relations crew to deal with journalists, and even a truck stocked with snacks and electrolyte drinks to keep firefighters sustained.