A family of five from Monroe died at a cabin in Brinnon, Washington early Sunday.
The Jefferson County Coroner identified the family as Jerry and Jenny Drake, both 42, and their three children, ages 2, 8, and 11.
The Jefferson County Sheriff's Office responded to a house fire around 1 a.m. Sunday. Neighbors reported hearing an explosion and said the hillside was on fire. Six neighboring agencies joined the firefight, but the small rental cabin was a total loss.
"This appears to be a tragic accident," said Jefferson County Fire District No. 4 Chief Tim Manly.
Manly says the Drakes were regular guests to the property.
"It was shocking," said neighbor Jim House.
Another neighbor Carleen Nelson said, "Your heart just sinks." She believes the family started spending their weekends in the cabin about a year ago. Nelson didn't know them but enjoyed having children next door.
"Just seeing them playing, riding bikes with their parents, it's heartbreaking," she said.
The Jefferson County Sheriff's Office sought help from the Washington State Patrol Crime Lab and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
Autopsies of the victims will be completed to determine the cause and manner of death, according to the Sheriff's Office.
The cause and origin of the fire remain unknown and may take several weeks to determine, fire officials said. Investigators do not think the fire was the result of a criminal act.
The Associated Press contributed to this report.