CLINTON — An overheated heat tape under a mobile home on Gustafson Road was the cause of a fire that destroyed the home on Christmas Day, the Office of State Fire Marshal has determined.

“The fire is being classified as accidental,” a notice issued Tuesday by Lt. Aaron M. Turcotte of the Maine Department of Public Safety states.

Turcotte in emails said that state fire marshal’s office investigators were called to the scene at 114 Gustafson Road at 2:56 p.m. Dec. 25 to help the Clinton Fire Department determine the fire’s origin and cause.

No one was home when the fire was reported by a neighbor around 12:52 p.m., according to Randy Caswell, Clinton’s second assistant fire chief.

Caswell said Thursday that when he arrived at the scene, the home was fully engulfed, with the fire coming out of the windows and door.

Though it was both Christmas and the start of Hanukkah, around 40 to 45 firefighters arrived at the scene to help battle the blaze, he said. Normally, around 15 people respond to a fire, he said.

Firefighters battled the fire for about four hours, with the Clinton Fire Department calling a second alarm for additional crews.

Because Gustafson Road is outside the fire hydrant district in town, added crews were needed to ferry water to the fire, according to Caswell.

“We called the alarm before we left the station and multiple towns arrived. We never ran out of water. Trucks were coming and coming,” Caswell said Thursday.

Firefighters from the Fairfield and Benton Fire-Rescue Department as well as from the Skowhegan, Winslow, Waterville, Canaan, Burnham and Oakland fire departments responded to the scene.