Dallas ? Southwest Airlines says a flight from Kansas City to Dallas lost cabin pressure, forcing passengers and crew to wear oxygen masks until the plane had descended to a safe altitude.

Spokeswoman Whitney Eichinger says no one was hurt and Flight 3201 landed safely at Love Field on Saturday evening.

Eichinger said Monday that the plane lost pressure at about 35,000 feet. She says the pilot followed protocol, descended and deployed the masks. The masks were not needed once the plane was below 10,000 feet.

Passenger David Wilding told WFAA-TV that the jet suddenly started to steeply dive. He says they wore the masks for about 20 minutes.

The plane was carrying 124 passengers and five crewmembers.

Eichinger says the jet underwent maintenance Sunday and returned to service Monday.