Delta Air Lines struggled to restart its worldwide operations after a computer failure halted flights for hours and grounded thousands of passengers.
About 365 flights were scrapped and delays and cancellations will continue even as systems come back online, the second-biggest U.S. carrier said Monday on Twitter. A power outage at Delta’s Atlanta base beginning at 2:38 a.m. local time interrupted computer operations, according to the airline.
The disarray at Delta marked the second time in less than a month that a system failure forced mass flight cancellations at a large U.S. carrier. Southwest Airlines, the biggest U.S. discount airline, said a disruption July 20 would cost it “tens of millions” of dollars after more than 2,300 flights were canceled.
Whether Delta had an adequate backup system “is certainly a legitimate question,” said Bob Mann, president of aviation consultant R.W. Mann & Co. and a former airline executive. “Why didn’t the backup systems perform, or what was it about the systems that if they performed, it still didn’t allow the systems to communicate?”
Delta fell 0.2 percent to $37.58 at 12:13 p.m. in New York.
As of 12 p.m. Monday, Delta said it had operated 1,260 of its almost 6,000 scheduled flights. The airline carried about 500,000 passengers daily during July, its busiest month, Delta said on its website.
Harold Jimenez, 29, had to re-book his ticket for Tuesday to fly to Nashville, Tennessee, from New York’s LaGuardia Airport. He was traveling to install cameras for a customer of the security firm where he works.
“I’ve been here since 6 a.m. I was supposed to takeoff at 8:40 a.m., and they told us it would be delayed until 11:30 a.m.,” Jimenez said. “But now they just canceled it.”
While the airline said it was giving snacks and beverages to passengers facing extended delays, passenger David Brennan at London’s Heathrow Airport said food vouchers ran out. He was scheduled to travel to San Francisco through Seattle on a 10-day vacation.
“I have two children. We have been here since 7:30 this morning,” he said. “It took two hours for them to tell us what had happened after the system went down. Then the pilot came and they said the flight was canceled because the crew can’t work more than 10 hours.”
Delta is waiving change fees and fare differentials on ticket prices for passengers whose flights were canceled or delayed Monday, according to a statement on its website. Passengers must begin their trip by Thursday.
Delta is booking inconvenienced travelers on other airlines in select cases but is largely accommodating them on its own flights, spokesman Michael Thomas said. No other airlines were affected, according to Hartsfield-Jackson Atlanta International Airport.
The likely cause was an “equipment failure at Delta,” a spokesman for electricity provider Georgia Power said.
Flight-status displays, the website and some mobile and airport technology were disrupted, Delta said. The carrier didn’t estimate how long repairs would take.
“This will obviously mean a financial burden on Delta as it will have to arrange for alternate travel and hotel costs for passengers who are booked,” said Mark Martin, founder of Dubai-based Martin Consulting. The airline would probably use agreements with other carriers to arrange alternative travel for some customers, he said.
Last month at Southwest, computers were restored after about 12 hours but flights continued to be canceled or delayed for several days as the carrier worked to get crews and planes in the right locations.
U.S. carriers experienced a series of technical disruptions to flights late last year and early in 2016, including a connectivity flaw at American Airlines that halted flights at its Chicago, Dallas and Miami hubs in September and a reservations-system glitch at Southwest in October.
A United Continental Holdings Inc. computer fault last summer lasted two hours and disrupted travel for thousands of fliers. It began with a router malfunctioning and prevented the carrier from ticketing passengers and dispatching crews.
Contributors: Andrea Rothman, Katerina Petroff, Anurag Kotoky, Dagney Pruner and Charlotte Ryan.