SANTA ANA — A California airport official says one of four emergency slides failed to deploy during a fire on a Southwest Airlines plane but the malfunction did not hinder the evacuation.

John Wayne Airport spokeswoman Deanne Thompson says all 139 passengers were safely evacuated Monday after smoke was reported just as the plane pushed back from the gate for takeoff.

Federal Aviation Administration spokesman Allen Kenitzer says the blaze was in the airliner's auxiliary power unit and was extinguished by the plane's fire suppression system. Thompson says the flames were out by the time fire crews arrived minutes later.

She says the evacuation went smoothly on the three functioning slides. A few passengers reported minor scrapes but there were no serious injuries.

The passengers were put on another plane to San Jose.