ATLANTA (RNN) - Although power has been restored after an 11-hour massive outage at Atlanta's Hartsfield-Jackson International Airport, delays and cancellations will continue to affect flights Monday.
Delta Air Lines, whose largest hub is at the Atlanta airport, has already canceled 300 flights for Monday, most of which are early morning flights into Atlanta.
The company says its flight schedule is expected to return to normal by Monday afternoon.
Authorities are encouraging passengers to check their flight statuses through their airline's website or app.
Several airlines are waiving change fees for passengers booked for Monday to, from or through Atlanta, according to the Atlanta Journal-Constitution.
Though power was restored shortly before midnight, more than 1,000 flights in and out of the airport were canceled Sunday.
Passengers were left stranded in Atlanta on grounded flights or in the airport's dark terminal.
According to Atlanta Mayor Kasim Reed, all passengers at ATL were de-planed by 10:00 p.m ET.
They were offered room to stay at the Georgia International Convention Center and free parking until 8:00 a.m. Monday.
Chick-fil-A, which is not typically open on Sunday, provided passengers with meals and water.
— Atlanta Airport (@ATLairport) December 18, 2017
Reed apologized during an evening news conference and said the power outage, which started shortly before 1:00 p.m., was caused by an electrical fire.
The fire damaged two substations serving the airport, including the system that provides backup power, according to CNN.
Security checks were done, and Reed says there's no sign the fire was set deliberately.
2/4 - We believe the issue may have involved a fire which caused extensive damage in a Georgia Power underground electrical facility. The fire was safely extinguished by fire crews before we could enter the area to assess damage and begin repairs.
— Georgia Power (@GeorgiaPower) December 18, 2017
After the outage, the Federal Aviation Administration called for a ground stop for flights headed to ATL.
"A ground stop means that flights headed to Atlanta are held on the ground at their departure airport," the FAA wrote on Twitter.
Hartsfield-Jackson, which serves 104 million passengers a year, is the world's busiest airport, according to the Associated Press.
The airport serves an average of 275,000 passengers daily, and nearly 2,500 planes arrive and depart each day.
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