UPDATE: 12:02 a.m. EST — The government for the city of Atlanta said late Sunday night the power at Atlanta’s Hartsfield-Jackson International Airport was fully restored. It also requested passengers to contact the airlines to check the status of their flights for Monday.

UPDATE: 11:41 p.m. EST — Atlanta Airport, in a tweet, said the power is back on in the Atrium and Concourses T, A, and B after a fire in the Georgia Power underground electrical facility caused a massive power outage Sunday, causing chaos at the airport and stranding thousands of passengers.

Original story:

Hours after passengers were left stranded at Atlanta’s Hartsfield-Jackson International Airport after a massive power outage Sunday, Mayor Kasim Reed said all the passengers were deplaned safely and that power was back at Concourse F.

The outage, which started with a fire in the Georgia Power underground electrical facility, caused the cancelation of 1,142 flights and delayed 250, NBC News stated quoting FlightAware.com.

Confirming the outage, Atlanta Airport authorities said: “A power outage has impacted several areas in the airport. The FAA tower can operate normally, however, departures are delayed because airport equipment in the terminals is not working.”

In a press conference Sunday night, Reed said: "Because of the intensity of the fire, the switch which accesses the redundant system was damaged." He also clarified that the fire damaged two substations that served the airport.

“We have no way of absolutely knowing, at this time, that our system may have been tampered with in order to create this kind of chaos and confusion,” he added, WSB-TV reported.

He also tweeted about the ongoing situation at the airport, stating that the power at Concourse F was back.

“Power at Concourse F is back on. If you are on another concourse, please remain there. We have an additional update on when full power will be restored from @GeorgiaPower,” he wrote on Twitter.

Stranded passengers were being provided meals by Chick-fil-A, Inc., which is also headquartered in Atlanta, Reed said, according to a Fox 5 Atlanta report.

Georgia Power, in a tweet, assured passengers of speedy repair work, saying it was continuing “to work quickly and safely to get power restored throughout the rest of the airport,” adding that the company expected to have the repairs completed by midnight.

Meanwhile, Twitter users swiftly reacted to the entire incident, posting photographs and videos of the chaotic scenes.

Many people tweeted saying they were stuck at the airport for hours and have been sitting on the runway at the airport. One passenger named Jared Greenberg wrote: “Our Pilot just said he was told that it is going to take Six hours to get power back up at the airport however they hope to have people deplaned in the next couple of hours.”