Delta Airlines flights have gradually begun to take off again.
Computer systems had crashed earlier on Monday, leaving planes grounded and passengers stranded at airports around the globe.
Delta said at 0840 EDT (1240 GMT) that a halt on departures had been lifted and some flights were resuming.
Have any flights taken off?
Flightracker website Flightradar showed a flight from Phoenix to Atlanta had taken off.
Three planes from Amsterdam to US destinations have also departed.
The US carrier also said the problems meant flight information was not showing correctly on Delta’s website or on airport information boards and this could take time to resolve.
(3 of 3) May be lag time in display of accurate flight status at https://t.co/kQzKJcUdth,Fly Delta app &
Delta</a> reps on phone, in airport.</p>— Delta News Hub (DeltaNewsHub) August 8, 2016
What caused the problem?
Delta says the problems resulted from a power outage in Atlanta overnight. It warned customers to expect “large-scale” cancellations.
The outage began at 0230 EDT (0630 GMT).
Were international flights affected?
Passengers were stuck in queues at check-in or on planes waiting to depart.
Delta operates 5,000 departures a day and is a member of the SkyTeam alliance alongside airlines like Air France-KLM.
It also partners for transatlantic flights with Virgin Atlantic, which said its flights were operating normally but cautioned that passengers should check tickets in case their flight was due to be operated by Delta as part of a code-share agreement.
kchappellnews) <a href="https://twitter.com/kchappellnews/status/762583477057269760">August 8, 2016</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> </p> <p> <blockquote class="twitter-video" data-lang="en"align="center"><p lang="en" dir="ltr">This couple were on their way to San Francisco for their wedding. They've had to cancel <a href="https://twitter.com/hashtag/DeltaAirlines?src=hash">#DeltaAirlines</a> <a href="https://t.co/kTZBaIEmLq">pic.twitter.com/kTZBaIEmLq</a></p>— Nick Boisvert (nickjboisvert) August 8, 2016
Is this the first time this has happened?
The glitch follows several high-profile computer problems faced by US airlines in the past year.
- Southwest Airlines – halted departures after technical problem in July
- American Airlines – suspended flights from three hubs last September due to a technical problem
Industry consultants say airlines face an increasing risk from computer disruptions as they automate more of their operations, distribute boarding passes on smartphones and fit their aircraft with Wi-Fi.