Airlines cancel thousands of flights amid winter storm chaos, with Southwest nixing 70%

(NEW YORK) — Airlines have canceled thousands of flights in what has become a Christmas nightmare for so many, as winter storms and staffing issues continue to cause havoc across the U.S.

Most major airlines have canceled or delayed thousands of flights, with Southwest Airlines canceling at least 70% of its flights Monday — more than 2,600 — due to a reported system meltdown. The airline has also canceled 60% of its flights for Tuesday.

On Christmas Day, 42% of Southwest’s flights were canceled and 48% were delayed, according to data from FlightAware. As of Monday night, data showed that nearly 4,000 flights had been canceled within, into or out of the U.S., while more than 7,700 had been delayed.

Jay McVay with Southwest Airlines said Monday night that “the sheer size of the storm” nationwide affected all major airports.

“It’s just the fact that this one started West swept east and impacted almost every single one of our largest airports that put us in a position where we struggled to recover, and we struggled to get our flight crews and airplanes where they needed to be,” McVay said from Houston’s William P. Hobby Airport.

Capt. Casey Murray, president of the Southwest Airlines Pilots Association, said in a statement earlier Monday that the ordeal has “been catastrophic.”

“It’s been a failure at every level at Southwest. Our pilots, our front-line employees have worked under enormous stress to try to get our passengers from A to B, but we were dealt a really bad hand as far as Southwest is concerned,” Murray said, in part, adding that their “processes,” information technology or infrastructure “just wasn’t there to support the operation.”

“And, unfortunately, our customers are bearing the brunt of it,” Murray added.

Angry Southwest customers took to Twitter on Monday, sharing their frustrations over the delays, cancellations and long hold times to speak to customer service agents.

“With consecutive days of extreme winter weather across our network behind us, continuing challenges are impacting our customers and employees in a significant way that is unacceptable,” Southwest said in a statement posted online. “And our heartfelt apologies for this are just beginning.”

Southwest said it is working to “address the wide-scale disruption” by repositioning its crew and planes, which were all in the wrong spots.

The Department of Transportation issued a statement Monday night, saying it’s “concerned by Southwest’s unacceptable rate of cancellations and delays and reports of lack of prompt customer service. The Department will examine whether cancellations were controllable and if Southwest is complying with its customer service plan.”

ABC News spoke with three stranded travelers — one staying overnight at an airport in Boston until her new flight, one stranded in Chicago after his flight got canceled and one driving with a stranger to make it to his Disney Cruise in Tampa after flight issues.

Each traveler blamed delays on staffing rather than the weather.

ABC News reached out to American Airlines, JetBlue, Delta and United to learn about how staffing is impacting their current delays and cancellations.

“I wanted to fly home for Christmas,” Laetitia Duler, who was flying home to San Francisco from Boston for the holiday, told ABC News. “As soon as I entered the line, they were just like, ‘your flights canceled. Like, bye.'”

Eric Jernigan was trying to fly from Jackson, Mississippi, to Tampa, Florida, for a Disney cruise when his Delta flight was canceled because of a lack of crew, he told ABC News.

He and five others decided to drive to Florida after getting stuck at Jackson-Medgar Wiley Evers International Airport.

The city of Buffalo, New York, initiated a travel ban as blizzard conditions moved into the area.

According to New York Gov. Kathy Hochul and local officials, 29 people have died in the state following the aftermath of an enormous lake-effect snowstorm.

Buffalo Niagara International Airport announced Monday that it will be closed until Wednesday as its crews work “around the clock” to get the airport back up and running.

ABC News’ Cherise Rudy contributed to this report.