A cleaning crew accidentally started a fire at the K mart on Channel Islands Boulevard about 4 a.m. Monday, causing about $50,000 in smoke and water damage, fire officials said.
The fire began after workers changed a propane bottle on a floor buffer, said Dan Gildea, inspector for the Oxnard Fire Department. Escaping fumes were ignited by a water-heater pilot light, he said.
No employees or firefighters were injured.
When firefighters arrived, cleaning employees were unable to get out of the building because they did not understand how to activate an emergency escape system, Gildea said.
"They weren't locked in per se, they just didn't understand how to get out," he said.
Just as firefighters were preparing to force the door open, a manager arrived with the keys to let the employees out.
The fire sprinkler system had kept the fire under control long enough in the rear storage area for firefighters to quickly extinguish it, Gildea said.