A complete power outage has stopped flight operations at Atlanta Hartsfield-Jackson International airport, with terminals in blackout conditions.
The outage occurred at 13:00 local time on 17 December and is believed to have been caused by a fire, says an airport statement. The airport is working with Georgia Power to resolve the issue.
Flights bound for Atlanta are being kept on the ground or cancelled. Flights already bound for Atlanta were diverted.
Media reports indicate that passengers stranded in darkened terminals have only mobile phones for illumination. Other passengers were trapped for hours on aircraft stuck on taxiways.
Atlanta's Hartsfield airport is among the world's busiest airports. FlightGlobal schedules data shows that both departures and arrivals average over 1,100 daily.
The airline most impacted by the issue is Delta Air Lines, which has its main hub in Atlanta. FlightMaps Analytics indicates that it accounts for 70.4% of traffic at the airport.
It said that over 900 Delta and Delta connection flights have been cancelled, and 48 flights diverted to alternative airports.
In a tweet at 20:29 local time, Delta said that it will continue deplaning aircraft that were unable to park at gates. It expects a full resumption of power on 18 December, but warns that delays and cancellations are likely.
Southwest Airlines is the second largest operator in Atlanta with about 18.7% of traffic, followed by American Airlines with 3.4%.