Electricity restored at Atlanta airport, world's busiest

Power has been fully restored at Hartsfield-Jackson Atlanta International Airport officials said, after an outage left passengers at the world's busiest airport stranded in darkened terminals or in aircraft idling on tarmacs on Sunday.

The airport lost power earlier in the day, halting all incoming and outgoing flights and leaving thousands stranded.

The airport announced on its Twitter page minutes after its midnight deadline, "Power has been restored on all concourses. 5,000+ meals are being delivered to passengers. Trains will be operational soon." Earlier, the airport said they expected to resolve the issue by midnight. 

Georgia Power, the utility that provides electricity to the sprawling airport, said in a statement that a fire caused extensive damage in an underground electrical facility, impacting substations serving the airport. 

The cause of the fire is not yet known.

Delayed departures

The partial shutdown at the start of one of the busiest travel weeks of the year forced the Federal Aviation Administration to ground flights bound for Atlanta. 

Departures from Atlanta were delayed as well because gates and other equipment inside terminals were inoperative, the agency said.

The FAA flight control tower was operating normally, but at least three major airlines – United Air Lines, American Airlines and Southwest Airlines –  suspended operations at the airport for the rest of the day.

"We know that today has been challenging to all of our customers travelling in and out of Atlanta, and we regret your disappointment," Southwest said in a statement.

Photos and videos posted on social media showed passengers huddled in partial darkness inside crowded terminals.

Delta Air Lines said on Twitter it was working to allow customers to deplane as quickly as possible, with only a limited number of open gates available.

Delta, which operates its largest hub at Hartsfield, said it cancelled more than 450 flights on Sunday.

For all carriers, more than 600 flights scheduled to fly out of Hartsfield, or 54 percent, were cancelled on Sunday while 449 of all scheduled inbound flights were scratched, according to FlightAware, an airline tracking service.