Family of 5, including 3 children, killed in cabin explosion: Washington state police

An explosion that decimated a cabin in Washington state also killed a family of five, including three children, authorities said Monday.

On Sunday, around 1 a.m., fire personnel and deputies with the Jefferson County Sheriff's Office responded to a report of a house fire in Brinnon, Washington.

"Neighbors reported hearing an explosion and stated the hillside was on fire and the house, a small cabin, was gone," the Jefferson County Sheriff's Office said in a statement.

Firefighters initially found two bodies at the scene, authorities said, then three others as they sifted through the cabin's ruins.

"The cause and origin of the fire remains unknown and may take several weeks to determine. At this point, investigators do not believe the fire happened as the result of a criminal act," the statement added. "Investigators believe the victims are a family of five, including three children and parents."

The identity of the victims and cause and manner of death are to be determined, pending an autopsy.

The sheriff's office said the Bureau of Alcohol, Tobacco, Firearms and Explosives is also helping in the investigation.