False Alarm

Ideally, people become accustomed to fire drills so that when there is a real fire, they will calmly gather their things and exit the building as practiced. After all, this is the point of such drills. But what if one person in the group consistently reacted in the opposite fashion? Write a situation in which a routine fire drill decends into chaos because one person insists, against all information provided by those in positions of authority, that everyone is in grave danger.