DALLAS -- Southwest Airlines says it has fixed the computer glitch that caused what the carrier called a "major outage" Wednesday and forced Southwest to cancel or delay hundreds of flights, reports CBS Dallas.
But the station says the backlog will have Southwest playing catch-up Thursday.
The Dallas based airline released a statement early Thursday saying, "Flexible rebooking accommodation will be available to customers once our systems are fully functional. Customers who are booked to travel Thursday, July 21, should check flight status information on Southwest.com and plan to arrive to the airport early, as long lines may occur."
Southwest Chief Communication Officer Linda Rutherford said I a tweeted video, "We know we've disappointed customers ... and we're really, really sorry about that. It's unacceptable to us. ... We know there are long lines at the airport and we really appreciate everyone's patience.
Southwest began having intermittent problems with several computer systems after an outage around 2 p.m. Central time.
Southwest briefly held planes at its gates, according to spokesman Brad Hawkins. Even after those planes resumed moving, delays piled up over the next several hours.
By late Wednesday night, the airline tweeted that it was still manually checking in passengers.
For about three hours, visitors to Southwest.com couldn't buy tickets, check in for flights, or check their flight's status. The site appeared to be working again by late afternoon, then crashed again.
Shortly before 10 p.m. Central time, 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.
Anxious customers tweeted to Southwest that they couldn;t check in for flights.
Leah Boyd and her husband, Matt, were flying to Providence, Rhode Island, but were held up at the Baltimore airport for three hours by mechanical issues with two different planes.
They finally boarded a plane, but after sitting at the gate for nearly an hour passengers were asked to exit because of the technology outage, Boyd said. Then the pilots reached the end of their shifts, so passengers waited for a replacement crew.
The Boyds ended up canceling their reservations and planned to drive to Rhode Island on Thursday instead. Leah figured it would be hard to find seats on another flight.
"I've never seen so many people in the terminal," she said. "All these people are going to be flying standby."
Airlines have sprawling, overlapping and complicated technology systems, and even brief outages can cause thousands of passengers to be stranded for hours.
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.