SAN DIEGO (CBS 8) - A fire alarm prompted evacuations inside Terminal 1 at Lindbergh Field Thursday.

Officials say the alarm was triggered around 10 a.m. by debris from a tile-cutting project.

Soon after, passengers started hearing announcements telling them to evacuate the area.

"They started saying everybody leave the building and I noticed a lot of people didn't take it seriously because there's been so many hoaxes," a traveler said.

It took fire crews about 20 minutes to investigate and determine there was no fire.

Passengers were allowed back through security in the order their flights were departing.