A computer malfunction on Wednesday took down Southwest Airlines airport kiosks nationwide and prevented passengers from checking in online through its web site, an airline spokesman said.

Kiosks at some airports were begining to come back online around 1:30 p.m., but remained dark at other locations, said Brooks Thomas. It was not immediately clear if kiosks at Minneapolis-St. Paul International Airport were operational. Passengers use the kiosks to print boarding passes.

When the airline's computer system went down around 11 a.m., all passengers had to see agents to get boarding passes.

That resulted in flight delays of 15 to 20 minutes.

Southwest Airlines operates 22 flights in and out of MSP each day. The Dallas-based airline serves 78 cities nationwide.