SNOHOMISH — Fire investigators who are still deciphering how a fire began at the former Seattle-Snohomish Mill site have ruled out all but two possibilities.
The Aug. 28 fire either started accidentally, or someone set it intentionally, the county fire marshal’s office said by way of the county’s spokesman.
But without new evidence to add — such as a witness who hasn’t stepped forward yet — then Snohomish’s largest fire in the past 10 years might result in a mystery on which cause it was.
Investigators have ruled out that utilities at the site or natural causes accidentally sparked the fire, the office said.
The fire destroyed the former mill’s lumber processing building, which faced the river. The metal building’s rooftop collapsed. Other buildings at the site weren’t damaged.
A mattress recycling firm had a lease at the building to store and sort inventory. Hundreds of mattresses fed the fire, with intense heat that challenged firefighters in their efforts.
Firefighters arrived after midnight to find the building fully involved. It took two hours to quell the two-alarm fire. Bright green flashes were seen from the center of the building during the fire.
County spokesman Kent Patton said earlier this year that no victims were found inside the burnt building.
The mill site’s owners did not have the burned building under an insurance policy.
Demoltion began on the building earlier this month. The site at 9525 Airport Way remains available to buy, either in portions or for the whole 33 acres.
The Seattle-Snohomish Mill closed in 2015 because of market saturation in the timber industry.
