Hundreds of Southwest Airlines flights across the country were delayed or canceled Wednesday after technology problems prevented many travelers from checking in or boarding flights.
Southwest began having intermittent problems with several computer systems after an outage around 2 p.m. Central time.
Southwest briefly held planes at their 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.
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.
Anxious customers tweeted to Southwest that they could not check in for flights.