Federal scrutiny is getting bigger. The CEO apologized to customers.

irate customers remained stranded, separated from their families and some still carrying Christmas gifts they planned to deliver days ago as the meltdown at Southwest Airlines entered its third day on Wednesday.

Southwest had canceled more than 2,500 flights, or 62 percent of its scheduled flights for the day, according to FlightAware. It could be days until normal service is restored.

Tearsa Aisani Parham stood in a line at the North Terminal of the Atlanta airport on Tuesday, hoping to find a Southwest employee who would listen. I am angry at how they did it.

Southwest has come under intense scrutiny after a winter storm last week disrupted travel plans across the United States. Thousands of customers have been left stranded and unable to rebook after Southwest's planes were unable to fly after the storm.

Almost a third of Southwest's flights were canceled on Friday. More than 20% of non-Southwest flights in the US were canceled on Friday.

The problems at Southwest worsened as other airlines regained their footing.

Southwest canceled 39% of its flights on Saturday. On Sunday, the number increased to 46 percent, on Monday to 74 percent and on Tuesday to 64 percent.

More than 11,000 Southwest flights have been canceled in the last week.

Pete Buttigieg, the transportation secretary, said in an interview on "NBC Nightly News" on Tuesday that it was "an unacceptable situation" that would require a closer look at Southwest's scheduling system.

He said that this has crossed the line from what is an uncontrollable weather situation to something that is the airline's responsibility.

The problems at Southwest Airlines over the last few days go beyond weather, according to a statement from the chair of the Senate Commerce Committee.

She said that many airlines failed to adequately communicate with consumers. An updated consumer refund rule is needed to protect consumers.

ImageSouthwest Airlines planes on the tarmac at Chicago Midway International Airport.
Southwest Airlines on the tarmac at Chicago Midway International Airport on Tuesday. The airline has canceled more than 2,500 flights on Wednesday.Credit...Taylor Glascock for The New York Times
Southwest Airlines planes on the tarmac at Chicago Midway International Airport.

Bob Jordan apologized to customers in a video on Tuesday night, saying that it would take days to solve the staffing problem.

The plan for the next few days is to fly a reduced schedule. We hope to be back on track before next week.

The issues are related to the carrier's "point to point" model in which planes tend to fly from destination to destination without returning to one or two main hubs. In a hub and spoke model, most airlines return their planes to a hub airport after flying out of other cities.

When bad weather strikes, hub-and-spoke airlines can shut down specific routes and have plans in place to restart operations. Southwest staff are not in a position to resume normal operations due to bad weather.

It leaves passengers like Ms. Parham scrambling to find alternatives.

A birthday gift to one of her sons and a Christmas gift to her grandson were among the gifts Ms. Parham planned to give her family after Christmas. She flew from Atlanta to Baltimore to meet up with her son, who doesn't like flying alone, then returned to Atlanta for a Christmas Day flight.

The family went to Disney. Her bags made it to the other side of the country.

She spent Christmas Day at the airport because her Sunday flight was not going to happen. She waited until 4:30 a.m. the next day and was told she would be placed on a flight at 6 a.m. Ms. Parham became a passenger because of the overbooking. The flight did not take off without her. There was a delay and then a cancellation of the next flight. There were two delays and a cancellation. The next flight after that? It was also canceled.

Ms Parham said she needed her makeup.

ImagePeople walk through piles of luggage.
Travelers searched for their bags in the baggage claim area at Dallas Love Field Airport in Texas on Tuesday.Credit...Emil Lippe for The New York Times
People walk through piles of luggage.

A man waiting in line at the Atlanta airport said that he wouldn't be able to get on a flight before Friday. After his Tuesday flight home was canceled, he had no choice but to go to the airport.

His twin brother was going to meet him in New York and he was eager to come home. Mr. Malloy visited a friend in Atlanta.

He said that to think that this is the way it has to end is not good.

Mr. Malloy was one of thousands of passengers who were affected by delays and canceled Southwest flights in June. He didn't receive his luggage for three days because he didn't use an airport car service. He received a flight voucher as an apology from the airline.

It might not have been a good idea to redeem the vouchers.

Daniel Victor was reporting from London.