A 59-year-old woman is believed to have died at home Saturday night in a fire in Penobscot County, police say.

Robin Stratton of Mattawamkeag lived in a single-family house that burned down from unknown causes, and Maine State Police recovered a body from Stratton’s bedroom that they believe is hers.

Stratton’s teenage granddaughter lived with her, but was not home, police said in a news release Sunday.

The medical examiner’s office will confirm whose remains were recovered from the rubble, likely with help from the Maine State Police DNA lab.

Neighbors on Main Street called in the fire around 8 p.m., and the house ultimately was destroyed. Because the damage was so extensive, state fire marshals say they can’t determine the cause of the fire.

This is the 18th fire death of the year, state police say.