By Keith Laing - 04/07/11 07:30 PM EDT
The plane, a Boeing 737-300, was in flight from Phoenix to Sacramento, Calif., when a large hole in its fuselage opened up, according to reports. There were 118 passengers and five Southwest employees on the plane, but no one was hurt.
The incident caused the Federal Aviation Administration to mandate that all airlines inspect their older 737s.
Southwest began an inspection voluntarily before the FAA order, resulting in hundreds of delays as 79 planes were checked. Five were found to have similar cracks and were taken out of service.