AUBURN – After spending the day sifting through rubble, fire inspectors were unable to pinpoint the cause of a Sunday afternoon fire at 21 Kilsyth St. that left a family of three homeless.

“The final findings are going to be that the cause is undetermined,” but electrical cannot be ruled out, said Fire Prevention Officer Gary Simard.

Simard worked at the site all day Monday with Chris Stanford, a state fire marshal, Charlie DeAngelis of Auburn’s electrical department, and an investigator from New England Fire Cause and Origin representing All State Insurance.

“We have the area of origin,” Simard said, “but because of the amount of damage we can’t tell – we know that electrical was in the area, and we couldn’t find anything else that could have started it.”

The fire started on the first floor back porch, Simard said. A wire could have been pinched or bent when the porch was added to the house years ago, he noted.

“There was older wiring that went different places that even the homeowners didn’t know about,” Simard said, adding that the ends were burned so badly inspectors could not trace the connections.

Family photos, a computer and Nathan Merrill’s guns were saved, primarily because firefighters got the heat out of a lot of areas and the items had a second layer of protection, like a closet, Simard said.