Delta Air Lines, are still struggling to restore operations two days after a faulty software update caused widespread technological issues, grounding numerous flights.
According to FlightAware, there were 1,461 flight cancellations within, into, or out of the U.S. on Sunday, with Delta and United Airlines leading the list.
Delta Chief Executive Ed Bastian informed customers on Sunday that flight cancellations persist as the airline works to recover its systems and resume normal operations. The system outage has led to over 3,500 canceled Delta and Delta Connection flights. Delta has been offering waivers to affected customers.
Bastian explained that one of their crew tracking tools was overwhelmed and unable to manage the unprecedented number of changes caused by the outage.
“The technology issue occurred during the busiest travel weekend of the summer, with our booked loads exceeding 90%, limiting our ability to re-accommodate passengers,” Bastian wrote. “I apologize to everyone impacted by these events.”
Transportation Secretary Pete Buttigieg spoke with Bastian on Sunday regarding the high number of cancellations since Friday. The Transportation Department reminded Delta of its obligation to refund passengers whose flights were canceled and who choose not to be rebooked.
“I have made clear to Delta that we expect prompt refunds for consumers who choose not to be rebooked, free rebooking, timely reimbursements for food and overnight hotel stays, and adequate customer service assistance,” Buttigieg said.
“No one should be stranded at an airport overnight or stuck on hold for hours waiting to talk to a customer service agent,” Buttigieg added. “Our department will support Delta passengers by enforcing all applicable passenger protections.”
This story was originally featured on Fortune.com.
