The agency released the results of its investigation into the Taylor Bridge Fire that blackened 36 square miles.
"I determine that the fire was human caused and was most likely caused by errant sparks and/or slag from the construction activity that was occurring on the bridge immediately prior to the fire's start," the report concluded.
The fire started Aug. 13 as a contractor and subcontractor were working on a Transportation Department project on the Highway 10 Bridge. Investigators found the fire started about 30 feet from where one worker was cutting rebar with a power saw on the bridge deck, while a second worker was welding under the bridge.
The work was taking place while industrial activity was supposed to be shut down because of the high fire danger in the area, the report said.
In addition to the 61 homes, the fire destroyed hundreds of outbuildings.
"This was a dramatic fire that was most dangerous in terms of its impact to home owners and property," said Bryan Flint, a spokesman for the agency, in a conference call with reporters
The report said work on the bridge was being performed for the Department of Transportation by bridge contractor Conway Construction Co., of Ridgefield, Wash., and subcontractor Rainier Steel, of Normandy Park, Wash.
But the DNR report did not issue any fines. And Flint said anyone looking to recover damages from the fire will likely have to go to court.
Flint said the DNR is required to seek recovery of its costs to battle the fire, which total around $5.5 million.
"We are working with the attorney general's office to determine who to seek the funds from," Flint said.
Flint said the fire started sometime between 1 p.m. and 1:20 p.m. on Aug. 13. Because of hazardous fire conditions that day, the DNR's Industrial Fire Protection Level required that the use of power saws and welding in the forest be concluded by 1 p.m., Flint said. But witnesses reported both activities occurred after 1 p.m., Flint said.
There was a water truck at the site being used to keep dust down, and it was driven to the fire, Flint said. But the person who drove the truck there did not know how to activate the water jets, the report found.
Workers at the construction site tried to extinguish the fire, also did not have the proper equipment and training to do so, the report found.
"The fire grew beyond their capacity to fight with shovels and one fire extinguisher," Flint said.
On the day the fire started, the humidity was a dry 14 percent, the temperature was 82 degrees and wind speed was 6 mph. That put the IFP Level at a 3, while the most dangerous level for fire potential is 4, Flint said.
It is relatively rare for a destructive wildfire to be started by industrial activity, Flint said. Most fires are started by lightning or untended campfires, he said.
More Northwest Headlines
Higher wages a surprising success for Seattle restaurant 3:37 p.m. Lawsuit over lease for Shell Arctic drilling fleet rejected 4:37 p.m. Court denies Medina millionaire’s release from Montana jail Woman, 87, goes missing while picking berries in Skamania County 7:04 p.m. Judge tosses lawsuit seeking Kurt Cobain death-scene photos 6:02 p.m. Medical examiner: Motorist hit by train killed herself 5:19 p.m. Salmonella outbreak that may be tied to pork grows 4:38 p.m. Man arrested for slaying in Clarkston
Our new comment system is not supported in IE 7. Please upgrade your browser here.