Delta says flights in the air are not affected by its computer problems.
Delta
Delta Air Lines is waing passengers of "large-scale" flight cancellations Monday due to computer system issues stemming from a power outage in Atlanta, where the carrier is headquartered.
Earlier, Delta tweeted that a computer outage had delayed flights, noting that flights already in the air weren't affected.
Delta said in a statement: "A power outage in Atlanta, which began at approximately 2:30 a.m. ET, has impacted Delta computer systems and operations worldwide, resulting in flight delays. Large-scale cancellations are expected today. All flights enroute are operating normally. 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."
There were indications of progress in getting systems back up to speed. A CBS News staffer at London's Heathrow Airport reported passengers were told Delta systems were back online and passengers were being checked in.
But an airline represetative in the US told CBS News that it was still in a "ground hold" and would not confirm or deny that the systems were back up.
WGCL-TV, the CBS affiliate in Atlanta, where Delta is based, reported that the problem was first uncovered when a flight was set to take off from San Francisco.