Delta Air Lines said it is recovering from a systems outage that caused departure delays and about 170 cancellations on Sunday night.
At 4am Eastern Time, the airline said around another 80 flights scheduled for today have been cancelled and noted that additional cancellations are possible.
Update: Delta said at 7am ET that 110 flights have been cancelled on Monday, with "a few" additional cancellations possible. It said it is "operating the vast majority of its flight schedule today" as the airline recovers from the systems outage.
"I want to apologize to all of our customers who have been impacted by this frustrating situation," said Delta CEO Ed Bastian. "This type of disruption is not acceptable to the Delta family, which prides itself on reliability and customer service. I also want to thank our employees who are working tirelessly to accommodate our customers."
Delta said that its "essential IT systems" went down about 6:30pm on Sunday, and had been restored a few hours later. It said all systems were back to normal shortly after midnight on Monday.
It said customers travelling today should check their flight status. A change fee waiver has been issued for customers scheduled to travel on January 29 and 30, for rebooking by February 3. Delta said unaccompanied minors will not be accepted for flights through noon ET today.
In August last year, the airline was hit by another major systems outage which forced it to cancel 1,800 flights and delay many more. In that outage the problem was traced to a malfunction in a critical power control module at the airline's technology command center, which caused a surge to the transformer and a loss of power.