BOSTON (CBS/AP) — A day after a computer outage in Southwest Airline’s system left hundreds of flights across the country cancelled, a long line of upset passengers gathered at the airline’s counter at Logan Airport.

The issues began around 2 p.m. Wednesday. Shortly before 11 p.m., Southwest said the outages had caused 600 to 700 canceled and delayed flights. Tracking service FlightStats Inc. put the numbers much higher — 400 cancelations and 2,000 delays.

One would-be flier from North Attleboro told WBZ NewsRadio 1030’s Doug Cope that he’s trying to get to a wedding in Denver, where he is supposed to be the best man. His flight’s been cancelled, but he’s taking it all in stride.

“We’re accepting donations for the flight that we need to re-book,” he said. “Anybody that’s gonna hear this, they can send that money to us, we’ll still be standing in line, probably, when they hear it.”

Another woman in line said she was told she could fly to Denver maybe Friday or Saturday.

“We always fly Southwest, never had a problem,” she said. “First time, I don’t know why.”

Southwest said that computer systems were gradually coming back, but it warned customers booked on Thursday flights to check their flight’s status online and arrive at the airport early because long lines were expected.

One woman trying to fly to Atlanta Thursday was unhappy the delays had stretched into a second day.

“I think it stinks,” she said. “If they knew last night, they should have informed people last night, we wouldn’t have been here at 3:30 in the morning.”

On Thursday morning, Southwest issued a statement saying they had most systems back online, but had cancelled more than 220 flights. The airline said it offered “flexible rebooking accommodation” through Sunday.

“We are focused on getting Customers and their luggage safely to their travel destinations and apologize to our Customers whose travel plans are impacted,” the statement read. “It’s never too early to say thank you and to extend our apologies and we want to share those sentiments both with our hard-working Employees and our loyal and understanding Customers, whom we hope to welcome back for a better experience soon. We’ll continue to work individually with our affected Customers to make this right.‎”

Last October, an outage caused about 800 Southwest flights to be delayed and forced employees to issue tickets and boarding passes by hand. The airline blamed a software application, and it recovered in about a day. United Airlines and American Airlines both had computer problems last summer but fixed the problems within a day.

Dallas-based Southwest Airlines Co. carries more passengers within the United States than any airline. However, it is far smaller than American, Delta and United when international traffic is included.

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WBZ NewsRadio 1030’s Doug Cope reports