Power has been restored to the world's busiest airport in Atlanta after an outage caused travel chaos for passengers, with more than a thousand flights canceled during the power cut.
A power outage at Hartsfield-Jackson Atlanta International Airport grounded operations on Sunday, stranding thousands of passengers. The outage lasted nearly 11 hours before power was finally restored around 11:45 p.m. E.T.
The disruptions continued on Monday with more than 400 flights canceled to or from the Atlanta airport. Airlines canceled 1,183 flights on Sunday, according to plane-tracking website FlightAware.
During the outage, the Federal Aviation Administration ordered a ground stop on flights, meaning planes are held at their departure points. Planes also were not departing the airport. The airport handles some 275,000 passengers a day.
Travelers posted photos on social media of fellow passengers sitting on the airport floor, dark departure halls, and staircases that were brought up to planes to disembark passengers after the electricity outage prevented the use of gates and jet bridges.
The power outage hit Atlanta-based Delta Air Lines particularly hard. The airline said it canceled close to 1,000 mainline and regional flights due to the outage and diverted 48 flights to other airports. It also canceled 300 flights scheduled for Monday.
Southwest Airlines canceled the remainder of its flights to and from the Atlanta airport on Sunday.
U.S. Customs and Border Protection said some international flights were sent to other airports.
Power was restored to terminals and for "all essential" airport activities shortly before midnight said Georgia Power, the airport's electricity provider. The company had said it "believed" the outage was caused by a fire that damaged an underground facility and affected substations serving the airport. Power to airport trains had been restored on Monday morning, the utility said.
More than 104 million travelers passed through Atlanta's airport last year, making the Delta Air Lines hub the world's busiest for passenger traffic, according to Airports Council International.
The airport handles around 2,500 arrivals and departures, according to the airport's figures.
The lack of electricity complicated efforts to get passengers off planes. Such delays can be costly for airlines. Airlines can face fines of up to $27,500 per passenger if a domestic flight is on the tarmac longer than three hours.
"Any flights that exceed the tarmac delay rule will start running up big numbers," said Gary Leff, a travel expert who writes the View from the Wing blog. He added that compensation given to travelers could be used to lower fines.
Passengers described the mayhem as confused travelers grappled with a lack of information and
Tami Litvak, a former flight attendant whose flight from Richmond, Virgina, to Atlanta was grounded on the tarmac at Hartsfield-Jackson for several hours, told CNBC that she has "been through a few emergencies" but "nothing as chaotic as this, ever."
She said disabled passengers were carried off the plane and during a long walk to the terminals, some volunteers carried senior citizens.
Litvak said she found a room at an airport Marriott, where travelers eager to grab a snack and find a place to sit, swarmed the hotel's lobby.
— CNBC's Ted Kemp contributed to this article