RANGELEY — A woman walking her dog Sunday night saw that a generator was on fire in a shed at 121 Bald Mountain Rd. and called 911 at about 8:20 p.m.

A tree had fallen and knocked out power to residences in the area. Some houses in the area have systems that automatically switch over to a generator once the power goes out, which was the case at the house on Bald Mountain Road, Fire and Rescue Chief Michael Bacon said Monday. The report of the fire came in about 30 minutes after the power went out.

Deputy Chief Mark Nedeau responded to the call and confirmed a fully involved outbuilding on fire with exposures to other buildings and propane tanks, Bacon said.

There were two 100-gallon propane tanks within 5 feet of the shed at the seasonal residence, he said.

Nedeau shut off the the propane supply line.

The name of the property owner was not immediately available, Bacon said. He plans to talk to the owner.

The cause of the burning generator is still under investigation, he said.