A small, off-the-grid house in the woods off Davis Road in Fairfield was destroyed by fire Thursday.

The fire, reported by a passerby at 3:30 p.m., may have started with a woodstove but the damage was too extensive to determine the cause, Fairfield fire Chief Travis Leary said.

“We’re labeling it as an accidental fire, Leary said Friday. “There was too much damage. It had already collapsed in on itself.”

He said a man lived in the 28 David Road house, which he estimated from the frame work to be 16-by-16 feet in size. The house had no power or running water and was heated by the woodstove, he said. Leary did not immediately have the name of the occupant, but estimated him to be middle-aged. He said the man reported he had filled the wood stove around 2 p.m. and left sometime after that, so wasn’t home when the fire broke out.

“He was actually getting jugs of water at another place, I think he said was on Six Rod Road at the time,” Leary said.

The house was not insured and no one was injured in the fire, he said. Firefighters left the scene around 5 p.m., he said.

“Everything that was inside there was definitely lost, for sure,” Leary said. “I offered the Red Cross, and he said he didn’t need it. He had other arrangements.”

The house was located on a private driveway, about 300 feet into the woods, according to Leary.

About 25 firefighters from Fairfield, Skowhegan, Waterville, Norridgewock and Oakland responded to the fire and Clinton firefighters stood by at the Fairfield station, he said. Delta Ambulance also was at the scene.

Davis Road is off Route 139, also known as Norridgewock Road, and turns into Ten Lots Road at the intersection of Six Rod and Martin Stream roads.