Southwest Airlines said over 500 flights were delayed on Sunday due to computer problems across its network but operations were expected to be back to normal on Monday.
“Teams worked throughout the night in advance of our first departures to ensure the smoothest operation today,” Southwest said in a statement Monday morning.
Problems arose early Sunday morning as the Dallas-based carrier had to use back-up systems to check in passengers who did not have printed or mobile boarding passes. Customers are unable to book tickets on Southwest.com as well. But the bigger problem was passengers unable to check in for their flights which led to long lines at ticket counters.
At some airports, like Las Vegas, long lines stretched outside of the terminal with some customers waiting several hours to check luggage and get boarding passes causing passengers to miss flights.
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“We have some additional work to do today to get bags delivered and some delayed or displaced Customers into open seats,” Southwest said. “We have teams working as quickly as possible to accomplish that.”
The airline said the 500 delayed flights represented about 25 percent of its 3,600 daily flight schedule. It continues to recommend that customers check-in online or on the airline’s mobile app before reaching the airport.
This is not the first time this year that Southwest has experience significant computer problems. In June, the airline extended an online fare sale for several extra days as its website was unable to keep up with the overwhelming demand.