Municipalities, once they are large enough, often operate an agency for fighting fires, and, in the U.S. and Canada, this agency is usually called the fire department. Airports, military bases, and other campuses with special needs may also operate their own fire departments. Fire departments employ specially-trained personnel, called Firefighters. They staff Fire engines, and, in some departments, Fireboats. Water bombers are employed to fight forest fires. The buildings used to house fire engines, when not in use, may be called a fire halls or fire stations.
Fire departments are a phenomenon of modern times and did not exist as such long ago.
In the 19th century, it was common for municipalities to provide the equipment firefighters required, while relying on volunteers to fight the fires. Some smaller fire departments still rely on volunteers, but most fire departments rely on full-time employees. During the transition from volunteer to full-time employees, many municipalities would hire one firefighter to be the chief firefighter, who would be responsible for training and organizing the volunteers, in addition to overseeing the department's administration. This one paid employee was widely referred to as the fire chief, and, this name persists in departments that rely on full-time employees.