Southwest Airlines says it's fixed the technology problems that delayed hundreds of flights Sunday and that it expects a normal day of operations.
The Dallas company had been warning passengers flying Monday to arrive at the airport two hours early and print boarding passes beforehand.
Airline representatives have not said what was causing the problem, but a spokesman has said there was no indication that hackers were behind it.
There were about 450 delays out of 3,600 flights scheduled Sunday.
Airline representatives have not said what caused the "technology issues," which affected the airline's mobile app, website and reservation centers.
but an airline spokesman said there was no indication that hackers were behind it.
The problem forced airline workers to manually issue tickets.