Passengers were allowed to return to their gates at the airport after an electrical explosion at a maintenance shop knocked out some power to one of the concourses, authorities said. No one was injured.
The explosion happened at about 8:40 a.m. at a maintenance shop near Gate D 21, said airport spokesman Reese McCranie.
McCranie said there was no fire, but the explosion caused minor property damage.
A unit that supplies power mostly to the air-conditioning system at Concourse D malfunctioned, McCranie said. He said that about 35 flights were delayed by 20 to 30 minutes.
The explosion briefly shut down power to part of the airport, Atlanta Fire Rescue spokeswoman Janet Ward said.
Officials plan to inspect the equipment Tuesday night to try to determine what led to the explosion, McCranie said.
An alternate power source was serving the concourse where the explosion happened.