A house fire that killed an elderly Mountain Ranch woman and her son this week remains under investigation.
The fire was reported at 12:46 a.m. Wednesday on the 8000 block of Mountain Meadows Drive in Mountain Ranch.
When Calaveras County Sheriff's deputies responded about 1 a.m., they found a single-family home fully engulfed in flames and were told two adults may have been trapped inside the home.
Two men escaped the fire, fire officials said.
The Calaveras County Coroner's Office confirmed that Barbara Grizzel, 86, of Mountain Ranch, was killed in the blaze along with her son, Harry Hanssen, 66, of Arroyo Grande.
Neighbor Jim Eckland, who lives across the street, said he didn't know Grizzel well.
However, "she was a very nice, sweet lady," he added.
Central Calaveras Fire and Rescue Protection District officials said there was a rescue attempt, but firefighters were forced out of the building by heavy fire conditions.
"As additional fire apparatus arrived on scene, the fire spreading to the nearby vegetation was extinguished and the fire in the structure was also extinguished," stated a Central Calaveras Fire report. "The residence incurred extensive damage."
Responding agencies were Central Calaveras Fire, San Andreas Fire, Mokelumne Hill Fire, West Point Fire, Altaville-Melones Fire, Angels City Fire, Calaveras County Consolidated Fire and Cal Fire.
Sheriff's detectives and Cal Fire arson investigators responded to investigate the fire.
The fire remained under investigation this morning and a cause has yet to be determined.