A technology glitch that grounded hundreds of Southwest Airlines flights Wednesday appeared to continue into Thursday morning.
Long lines formed at the Southwest counter at Philadelphia International Airport Thursday morning after the airline canceled early flights to Albuquerque, Atlanta, Chicago, Las Vegas, Nashville and San Diego. Other flights to Atlanta, Dallas and Myrtle Beach were delayed.
Southwest Airlines canceled more than 220 flights by 7:30 Thursday morning, said Southwest.
"Most of our systems are back online this morning following yesterday's technology outages, but recovery will take some time," said the airline in an online statement. "We expect some cancelations and delays as we position aircraft and crews."
Across the country, Southwest flights 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 3 p.m. Eastern time Wednesday.
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.
The airline promised to "work with each and every affected Customer to make this right."
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.