MIAMI — Delta Air Lines has grounded flights after experiencing a computer outage throughout its system. The Atlanta-based carrier warned of “large-scale” cancellations and delays.

The airline informed that the outage began at around 02:30 EDT (06:30 GMT), affecting the airline’s computer systems and operations worldwide.

“We are aware that flight status systems, including airport screens, are incorrectly showing flights on time. We apologize to customers who are affected by this issue, and our teams are working to resolve the problem as quickly as possible,” Delta said in a statement.

At 08:40 EDT (12:40 GMT) the airline announced the lift of its ground stop, and limited departures are resuming. According to, the first U.S.-based Delta departure was flight DL1747 from Phoenix to Atlanta.

“Customers heading to the airport should expect delays and cancellations. While inquiries are high and wait times are long, our customer service agents are doing everything they can to assist. There may also be some lag time in the display of accurate flight status at, the Fly Delta App and from Delta representatives on the phone and in airport,” Delta said.

As of 13:30 EDT (17:30 GMT), the airline  had canceled 451 flights, while operating about 1,680 of its nearly 6,000 scheduled flights so far. In a video, Delta CEO Ed Bastian apologized to customers for the operational disruption, assuring that airline employees are working “all hands on deck” to bring flight schedules back to normal.

“For those of you who have been inconvenienced and need to access and make changes to your travel plans, we have instituted system-wide waivers and you can access those either through or by talking to any of our reservation agents.” Bastian said.

On Tuesday, Delta cancelled 775 flights as the airline worked to establish normal operations. These disruptions are additional to 1,000 flights cancelled and 3,000 flights delayed on Monday. The airline anticipates returning to a normal operation by mid-to-late afternoon Wednesday.

“We were able to bring our systems back on line and resume flights within a few hours yesterday, but we are still operating in recovery mode,” said Dave Holtz, Senior Vice President – Operations and Customer Center. “We are doing everything we can to return our operation to normal reliability, but we do expect additional delays and cancellations.”

Computer outages are not unusual for airlines and travelers. Last month, Southwest Airlines was forced to cancel over 2,000 flights across the U.S.A. after IT issues that prevented travelers to check-in or board flights.