A rogue fire alarm forced the evacuation of people at Lindbergh Field's Terminal 2 for about 20 minutes Saturday, airport officials confirmed.
The alarm sounded around 7:30 p.m. at the San Diego International Airport, setting off emergency lights as well.
Officials say the sprinklers were triggered outside the terminal to wet the building down, but no one inside was sprayed.
An unknown number of people were forced to evacuate from about 7:30 p.m. to 7:50 p.m.
Shop clerks told NBC 7 that the place was emptied out and the security checkpoint was shut down in one part of the terminal.
Passenger Martin Asbosedo was evacuated onto the runway as he was going through the passport checkpoint. He had just landed on a flight from Italy.
"It was very calm. I was surprised," said Asbosedo. "Nobody was running. Everybody was laughing. At first we think it was a joke or something like that."
So far, there have been no reports of flights impacted, according to the airport.
Officials are still trying to determine what caused the rogue fire alarm to go off.