More than 1,500 US flights canceled for the third day straight as airlines slowly recover from global tech outage

(CNN) — More than 1,500 US flights have been canceled for the third day straight, as airlines struggle to recover from a global tech outage that left thousands of passengers stranded at airports.

Around 1,600 flights into, within or out of the United States were canceled by Sunday evening, while more than 8,500 US flights were delayed, according to the tracking website FlightAware.com.

More than 1,000 of those cancelations were from Delta Air Lines, the website shows.

The airline is continuing its recovery efforts following “an outside vendor technology issue” resulting in delays and cancelations, Delta said Sunday. The airline is communicating directly with some impacted customers, offering travel vouchers, waivers and SkyMiles Program miles, it said.

Recovery still ongoing

In an update to Delta customers Sunday afternoon, Delta Air Lines CEO Ed Bastian said the airline’s teams are still working to recover their system and restore operations.

“Canceling a flight is always a last resort, and something we don’t take lightly,” Bastian said.

On Saturday, 2,136 flights among multiple carriers were canceled, and more than 21,300 flights were delayed, according to FlightAware.

The issue extended beyond airports, with businesses, government agencies, health and emergency services, banks, schools and universities around the world grinding to a halt or seeing services disrupted due to a flawed software update for Microsoft Windows operating systems issued by the cybersecurity firm CrowdStrike, experts told CNN.

The outage affected an estimated 8.5 million Windows devices, according to Microsoft.

CrowdStrike CEO George Kurtz apologized to customers and said a fix has been deployed, but experts say getting systems back in order will be a lengthy process.

Major airlines have said services are being restored, but there could be more delays and disruptions.

A majority of United Airlines systems have recovered from Friday’s outage, though some delays and cancellations are still possible, the airline said in a statement. More than 400 United flights were canceled Saturday, and over 200 flights were canceled Sunday, according to FlightAware.com.

Unaccompanied minors

Delta has paused unaccompanied minor travel until Wednesday due to the outage, the airline announced over the weekend. Unaccompanied children who are already booked on a Delta flight will not be able to travel, and the airline has asked that no new flights be booked for them.

Also impacted was American Airlines, which said in a statement Friday “we were able to safely reestablish our operation” and it had “issued a travel waiver for our customers impacted by the vendor technology issue earlier this morning.” Allegiant Air said in a statement Saturday while “normal operations have resumed” after the outage, they’re processing a backlog of customer messages and troubleshooting their programs and platforms.

Even with the flawed computer update rolled back, it’s not a quick fix for airlines, which have computers at thousands of gates that will need to be individually manually rebooted, David Kennedy, cofounder of cybersecurity company Binary Defense, told CNN on Saturday.

“It’s not just as simple as rebooting. There’s a lot more steps and complexities in this that are involved,” Kennedy said. “There’s just not enough people at those airports, at those locations to go and do it.”

The US Department of Transportation on Friday said it determined the flight delays and cancelations resulting from the system outage were “controllable,” meaning they’re “attributable to the airline.” In such cases, the airlines “must adhere to their customer service commitments.”

Transportation Secretary Pete Buttigieg in a social media post Saturday said he received reports of some airlines only offering flight credits to passengers for canceled flights.

“Let me be clear — you are entitled to get your money back promptly if your flight is canceled and you don’t take a rebooking,” Buttigieg said.

Travelers upset as plans are thwarted

Flight cancelations persist at the world’s busiest airport, Atlanta’s Hartsfield-Jackson International Airport, where officials have implemented a “concessions crisis plan, ensuring concessions availability while all flights are operating.”

“We’ve provided assistance and guidance to passengers spending the night in the airport, and we’re collaborating with our airlines to create space for luggage reunification areas,” an airport spokesperson told CNN on Sunday.

“It just seems like nobody cares about us. We’re sleeping on the floor. There’s kids sleeping on the floor and no one’s done anything about it,” traveler Anthony Augugliaro told CNN affiliate WSB on Sunday.

Long lines of passengers also waited for assistance at the airport Saturday. Delta passenger Catalina Villareal described the scene: “Mayhem. Chaos. Frustration. Hunger.”

Villareal said she had experienced three flights cancellations.

Charlotte Yeh, a traveler at Boston Logan International Airport, told CNN affiliate WFXT Saturday she received no notification her flight to Fort Lauderdale for her father’s 96th birthday was canceled.

Uncertainty looms as answers still sought

Thousands of people face the same uncertainty as they cram together in airports across the country, waiting for answers.

“I was supposed to be in California for my mom’s wedding,” Richard Whitfield of Pasco County, Florida, told CNN on Saturday. Whitfield and his partner, Jonathan Shade, left Tampa on Thursday and missed their connecting flight in Atlanta due to poor weather conditions, delaying their landing and forcing the plane to refuel in Tallahassee.

After their rescheduled flight on Friday was delayed many times, the couple decided to cancel the trip and just head home. But with no available flights back to Tampa on Friday night, they spent their second night in an airport hotel. They were unable to get a voucher from Delta for either of their stays.

“(Richard has) been on hold for 24 hours,” Shade told CNN. “When he eventually got his number in line, it was 2,001.”

Two hours later, Richard’s place in Delta Air Lines’ virtual customer service queue was 2,300 in line, Shade said.

Whitfield told CNN the whole ordeal has had an impact on him.

“For me, it’s been the domino effect that it has on humanity and everything that we need to survive: food, sleep, or water, housing,” he said.

After spending 48 hours in Atlanta, they found a Saturday evening flight back to Tampa they say they can only hope is not delayed or canceled. For now, there is nothing the couple can do but wait and “get a good stiff drink,” Shade and Whitfield said.