The world's busiest airport, in the US city of Atlanta, said early Monday that power was back on after an outage left passengers in the dark and affected hundreds of flights.
"Power has been restored on all concourses," the Hartsfield-Jackson Atlanta International Airport said on its Twitter account, about 11 hours after first reporting an electrical disruption.
Giving an idea of how many people were affected, the airport added: "5,000+ meals are being delivered to passengers."
LIGHTS ON and delivering food and water to our passengers! Thank you @dancathy with @ChickfilA for opening on a SUNDAY! #ChristmasMiracle pic.twitter.com/0PlSxHIWj5
— Atlanta Airport (@ATLairport) December 18, 2017
It did not indicate how long it might take to clear the backlog of flights but said it was offering affected passengers "free parking until 8am", or for about eight hours after the lights came back on.
Flightview.com, which tracks air travel data, listed hundreds of flights as being delayed, cancelled or diverted since Sunday afternoon, but it also began to show several departures as scheduled for 6am Monday.
The Georgia Power company, in a statement, said that "power had been restored for all essential airport activities including all concourses and flight operations".
It described the outage as "very rare". Although the exact cause is not yet known, Georgia Power said preliminary investigation suggested that a fire damaged cables and caused the power disruption.
"No personnel or passengers were in danger at any time," the company said.
Photos and videos from the airport showed people walking or sitting in crowded airport corridors, with windows only partially cutting through the gloom.
Numerous airplanes could be seen parked on the airport tarmac.
A woman said she was waiting in the security line when "they turned off the lights — a few times they went off, and then finally they shut off completely".
One passenger, Mike Vizdos, told AFP that he and other passengers got trapped on their aircraft because the power went out just as it reached the terminal gate after arriving from Costa Rica.
"Sat on the plane for six hours and then cleared customs and immigration, Mr Vizdos said, still hoping to reach his home in Richmond, Virginia the following day.
"There are thousands of stories," he said.
The airport earlier announced that it "sustained a power outage shortly after 1pm today [Sunday]".
That led the Federal Aviation Administration to place a "ground stop" on flights inbound for Atlanta, meaning they are held at the airports from which they were to depart.
"The FAA Tower can operate normally, however, departures are delayed because airport equipment in the terminals is not working," it said on Twitter.
Those stuck at the airport were predictably not amused.
"I haven't eaten since 8am central," one user tweeted.
Others said people were not being permitted to leave the airport, including a mother who tweeted: "My kid is trapped with the others at the Atlanta airport. No one is allowed to leave. Isn't this kidnapping?"
