A neighbor reported the fire shortly before 9 p.m. Firefighters also were told that someone living in the home was believed to still be inside.
By the time firefighters were able to reach the two-story wood home on a hillside, there was little they could do.
"It was clear right from the get-go that it was a defensive fire," Snohomish County Fire District 21 chief Rick Isler said.
Firefighters and equipment from five fire districts were brought in to battle the blaze. The response included four engines and six tender trucks. There are no fire hydrants in the area.
"With the time of day and amount of crew we had available, it was just expedient to have additional crews there to keep them fresh," Isler said.
Early Sunday morning, detectives and firefighters searched the house and discovered the woman's body inside.
Identification of the victim, as well as cause and manner of death, are pending from the Snohomish County Medical Examiner's Office.
"We are working with the county fire marshal and Snohomish County Medical Examiner to determine if there is anything suspicious about her death," Ireton said. "At this point, we don't have any evidence to say otherwise."
The Snohomish County Sheriff's Office Major Crimes Unit is investigating the circumstances leading to the victim's death, Ireton said.
Eric Stevick: 425-339-3446, firstname.lastname@example.org
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