Southwest Airlines is working to resolve a major glitch in its computers that began over the weekend.
The glitch is responsible for hundreds of delayed and canceled flights, and more delays are possible today, the company says.
Southwest says the "tech problem" began Sunday, sending workers who process passengers to manually write tickets.
Passengers experienced long lines at airports across the country.
A spokesperson for Southwest says about 450 of the 3,600 flights schedule for Sunday were delayed.