Here's what caused the power outage at Atlanta airport

ATLANTA — Georgia Power crews are working to restore power at Hartsfield-Jackson International Airport.

An outage was reported around 1:00 p.m. Sunday. The company expects power to be restored by midnight.

We're monitoring the situation at the airport through the night and will bring you th latest on WSBTV.com and Channel 2 Action News this Morning

Georgia Power believes the outage was caused by a fire that led to extensive damage in an underground facility.

Atlanta Mayor Kasim Reed said it took almost two hours to contain the fire. He said because of the strong fumes from the flames, Georgia Power crews could not access the facility immediately.

Georgia Power said the switch that accesses the back-up power system was also damaged in the fire, causing both systems to go down.

“The airport has a very redundant, very robust system," a Georgia Power spokeswoman said.

Once the fire was extinguished, Georgia Power crews assessed the damage and began repairs.

[READ: Passengers frustrated, confused by airport power outage: 'It's crazy in here']

Power was restored to Concourse F around 7:30 p.m.

Officials said they do not know what caused the fire and it will take time to investigate.

"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," Reed said.

The FAA ordered a ground stop on all flights headed to the airport due to the power outage.International flights into Atlanta are being diverted to other airports.

Major airlines JetBlue, Delta Airlines, United Airlines, Southwest and American Airlines have canceled all flights for the remainder of the day.

Cox Media Group