A fire drill is a method of practicing how a building should evacuate in the event of a fire or other emergencies. In most cases, the building's existing fire alarm system is activated and the building is evacuated by means of the nearest available exits, as if an emergency had actually occurred. Fire drill procedures may vary depending on the building type, such as hospitals or high rise buildings, where occupants may be relocated within the building as opposed to evacuating the building. Generally, the evacuation interval is measured to ensure that it is fast enough, and problems with the emergency system or evacuation procedures are identified so that they may be remedied.