text: In addition to fire drills, most buildings have their fire alarm systems checked on a regular basis to ensure that the system is working. Fire alarm tests are often done outside normal business hours so as to minimize disruption of building functions; in schools, they are often done when students and staff are not around or during the holidays where specialist fire alarm engineers test alarms in the building for repair if needed.
  History of fire drills
  The purpose of fire drills in buildings is to ensure that everyone knows how to exit safely as quickly as possible if a fire, smoke, carbon monoxide, or other emergency occurs, and to familiarize building occupants with the sound of the fire alarm.
  Before regular fire drills were instituted, an infamous fire broke out at the private Catholic school Our Lady of the Angels in 1958, in Chicago. Children on the second floor were trapped there, with neither teachers nor pupils knowing how to get out of the building safely. Many children jumped out of windows, and many were killed as they could not make their way to an exit. Although the school had passed a fire inspection only two months before, and had the number of fire exits and fire extinguishers required at the time, it lacked smoke detectors or adequate fire alarms, and was overcrowded.