RALEIGH (WTVD) -- At least half of all Delta Air Lines flights Monday were delayed or canceled after a power outage knocked out the airline's computer systems worldwide.
About 14 hours after the outage at one of its facilities, Delta was struggling to resume normal operations and clear a backlog of stranded passengers. It sought to appease frustrated customers by offering refunds and $200 travel vouchers.
The Atlanta-based carrier grounded flights early Monday after a power outage hit its computer systems globally around 2:30 a.m. Eastern. About 6 hours later, the airline lifted the ground stop and limited departures resumed. However, Delta said travelers headed to airports should expect delays and/ or cancellations.
Flights which were already en route were operating normally, but many passengers took to Twitter to express frustration with being stuck on the ground.
"We are aware that flight status systems, including airport screens, are incorrectly showing flights on time," the company said in a statement. "We apologize to customers who are affected by this issue, and our teams are working to resolve the problem as quickly as possible."
Confirmation of the troubles first came in an official account that responds to customers via Twitter. The company had said its IT systems were down "everywhere" and "hopefully it won't be much longer."
Several applications were affected, including the company's website. Delta said it is offering a waiver to customers who are affected.
At Raleigh-Durham International Airport, long lines snaked around the ticket counters early Monday morning as travelers said the airline did not alert them about the outage before they headed to the airport.
"This is crazy," said traveler Kara Hart said. "Thousands of people, probably, in here!"
"They don't send alerts to people, so you know? No. No alert, no e-mail," said Kim Demarco, who was trying to get to Buffalo, New York.
Delta has about 120 flights in and out of the airport per day.
In June, Delta Air Lines had the most passengers at RDU, accounting for more than 29 percent of all traffic.
Among those affected by the situation were newlyweds Kara and Dakota Hart who were slated to head to St. Lucia for her honeymoon early Monday morning.
"We only have six days in St. Lucia and we have a big excursion planned for tomorrow, so we're really hoping we get there today," Kara said.
More than three hours after their scheduled departure, their honeymoon flight left RDU.
Airline data company Flightaware said there were at least 858 cancellations and 7,359 delays across the global industry on Monday morning. It's unclear how many are related to Delta's problems and whether Delta's groundings are reflected in the numbers.
Computer outages have caused major headaches for airlines and travelers before. Southwest Airlines was forced to cancel more than 2,000 flights across the U.S. last month after technology problems prevented many travelers from checking in or boarding flights.
The Associated Press contributed to this report.