During one of the fire drills when I was going to school, one teacher was like “we should test whether the smoke alarms actually work” and lit a small fire in a small metal bin. Plot twist was that the smoke detectors on this side of the school did not work, but when the smoke got to the other side of the school it worked and triggered the alarm. Only at that time all the pupils were already on their way back into the building again and panicked when they noticed smoke and a new alarm.