The tower at Fort Lauderdale-Hollywood International Airport was briefly evacuated Thursday morning after air traffic controllers reported smelling fumes and seeing a puff of smoke, according to the Federal Aviation Administration.
Firefighters determined that the smoke was caused by a problem with the air conditioner.
Air traffic controllers were allowed to return to the tower about 7 a.m.
The FAA Terminal Radar Approach Control in Miami, which provides radar service for Fort Lauderdale-Hollywood International Airport, handled flights safely until air traffic controllers returned to the tower.
Airport spokesman Allen Siegel said 12 departing flights were delayed as a result of the incident.
The FAA said technicians are working to repair the air conditioner.