LEWISTON – A contractor working on a Cloutier Street apartment house Tuesday believes he may have caused a fire on the second floor.

Fire officials say the contractor also kept the fire from raging out of control.

Bruce Sanford, a volunteer firefighter himself, said he was cutting into the bottom of a window when a spark appeared to have ignited a section of a wall.

When police and firefighters first arrived at about 3:30 p.m., flames were shooting from the second floor window in the building behind Androscoggin Bank near the corner of Sabattus and Farwell streets.

Sanford, who had made the call for help, was fighting the fire with a garden hose.

Fire crews quickly doused the flames and tore into walls to snuff out hot spots. Nobody was hurt in the blaze.

Lewiston fire investigator Paul Ouellette was called to the scene and said the fire was accidental, caused when a spark flew from Sanford’s grinding tool.

Ouellette said Sanford helped keep the flames from spreading into the attic when he battled them with a garden hose.

“If it had gotten into the attic, it would have been much worse,” he said. “We would have had to call in Auburn. We’d still be over there.”

Instead, damage was limited to one room. Ouellette estimated the amount of damage at $5,000.