Delta Air Lines says limited flights have begun several hours after a computer outage grounded its flights around the world and stranded thousands of people.
The Atlanta airline said Monday that delays and cancelations are ongoing.
As of about 10:20 a.m. Pacific time, 427 of the airline's 6,000 scheduled flights worldwide had been canceled.
Around two dozen morning and early afternoon flights into or out of Lindbergh Field in San Diego were delayed, according to flight status information on the airport's website. However, later flights shown to be arriving or departing on time may also be delayed or canceled.
"I apologize for the challenges this has created for you with your travel experience," Delta CEO Ed Bastian said in a video posted online.
"The Delta team is working very, very hard to restore and get these systems back as quickly as possible," Bastian said. "For those of you who have been inconvenienced and need to access and make changes to your travel plans, we have instituted system-wide (fee) waivers, and you can access those through either Delta.com or by talking to any of our reservation agents."
The airline also said there may be some lag time in the display of accurate flight status at Delta.com, the Fly Delta App and from Delta representatives on the phone and in airport.
The airline says that a power outage at a facility in Atlanta at around 2:30 a.m. Eastern started the cascading meltdown.
Flights that were already in the air when the outage struck continued, but many flights remained grounded. Over the next several hours, only a handful of flights took off instead of the usual hundreds, according to flight-tracking services.