POWER has been restored to the world’s busiest airport, but travel woes are expected to linger for days after thousands of people were left stranded yesterday morning in Atlanta.

More than 1000 flights have been grounded at Hartsfield-Jackson Atlanta International Airport due to Sunday’s power outage.

A sudden power cut which Georgia Power said was caused by a fire in an underground electrical facility brought the airport to a standstill on Sunday afternoon.

All outgoing flights were halted, and arriving planes were held on the tarmac as international flights were diverted.

Delta Air Lines, which has its biggest hub in Atlanta, will be hardest-hit. By Sunday evening, Delta had cancelled nearly 900 flights and another 300 yesterday, nearly all of them in Atlanta.

Robert Mann, an aviation consultant and former American Airlines executive, said it will likely be today before Delta’s operations in Atlanta return to normal, and for passengers “it could be most of the week” because there are not many open seats on other flights in the last week before Christmas.

American Airlines cancelled 24 departures and an equal number of arrivals on Sunday.

Georgia Power said they believe a piece of equipment in an underground electrical facility failed, causing the fire, which was next to equipment for a backup system, causing that to also fail.

“No personnel or passengers were in danger at any time,” the statement said.

No areas outside of the airport were affected by the power loss. The utility said there are “many redundant systems in place” to ensure the power supply to the airport and that such outages at the airport “are very rare”.

Anthony Foxx, who served as US transportation secretary under former president Barack Obama, tweeted that he was among the many travellers stuck for hours on a plane on the tarmac.

“Total and abject failure here at ATL Airport today,” he tweeted, adding that there was “no excuse for lack of workable redundant power source. NONE!”

In another tweet, Foxx said it seemed like the problem was “compounded by confusion and poor communication”.