A power outage Sunday at the nation's busiest airport has cancelled or delayed more than 50 flights to Atlanta out of New York City area airports.

Officials said around 7:45 p.m. that power had been restored to at least one concourse at Hartsfield-Jackson Atlanta International Airport.

On its Twitter page Sunday night the airport tweeted, "Power on Concourse F is back ON! We are working with great urgency w/ @GeorgiaPower to restore power throughout rest of airport."

Power had been out at the airport since about 1 p.m. All flights coming into and going out of the airport were halted.

As of 8:37 pm., at least 70 flights to Atlanta out of Kennedy Airport, LaGuardia Airport, or Newark Airport had been either delayed or cancelled Sunday.

For more information about a flight's status, check the websites for JFK Airport, LaGuardia Airport, or Newark Airport.

Delta Airlines, which has its headquarters at the Hartsfield-Jackson Airport, canceled about 450 mainline and regional flights.

Officials said the airport is also diverting international flights.

Georgia Power said in a statement Sunday that a fire caused extensive damage in an underground electrical facility, impacting substations serving the airport. The cause of the fire is not yet known.

The Hartsfield-Jackson Airport serves about 275,000 passengers daily, with nearly 2,500 planes arriving and departing each day.