Hundreds of flights were canceled at Hartsfield-Jackson Atlanta International Airport on Monday after a fire in an underground electrical facility brought chaos to the world’s largest airport the previous day.

The fire resulted in a power outage at the airport that lasted for several hours on Sunday.

An article from the Associated Press stated that “it could be days before Delta Air Lines, which has its hub in Atlanta, can resume normal operations.” The fire also caused the airport’s backup power system to fail.

Power was restored to the airport at around midnight, but for the hours that electricity was out thousands of travelers were forced to wait on planes or in the terminals. The Associated Press also noted in its reporting that travelers with disabilities had to be carried down stairs and escalators until the power was restored.

Inbound flights were diverted to other cities and outgoing flights were halted during the power outage.

Former U.S. Transportation Secretary Anthony Foxx, who served under former President Barack Obama, blasted airport officials, saying the problem was “compounded by confusion and poor communication.”

More information and developments are available from the Associated Press, USA Today and NBC News.