A state Department of Natural Resources investigation has concluded that tree branches chafing on a power line triggered the Aug. 19, 2015, fire near Twisp that claimed the lives of three U.S. Forest Service crew members.
The investigative report into the cause of the Twisp River Fire was obtained by The Seattle Times under a public records request.
The report found that the ignition likely occurred as a light wind swayed both the branches and a sagging distribution line operated by the Okanogan County Electrical Cooperative.
Burning foliage then dropped to the ground to spread flames that threatened homes and drew in fire crews, according to the investigation.
“The fire danger rating for that area was categorized as very high, which indicated fires would start easily from all causes and immediately after ignition would spread rapidly and increase quickly in intensity,” stated the report.
The report offers stark evidence of the fire risks that the region’s network of power lines can create when they come into contact with trees during the peak summer fire season.
The Aug. 19 fire, some 6 miles west of Twisp, killed Richard Wheeler, Andrew Zajac, and Tom Zbyszewski, and critically burned Daniel Lyon Jr. The deaths and injury were a wrenching blow for the Methow Valley community — and the broader firefighting community — occurring during a historically bad fire season that burned more than 1.8 million acres in Washington and Oregon.
The Twisp River Fire eventually burned more than 11,220 acres and destroyed or damaged some rural residences outside Twisp.
The fire path crossed state and private lands the state Department of Natural Resources is responsible for protecting. By law, the department is required to investigate forest fires on those lands and can seek to recover costs for fighting those fires that may be associated with negligence.
The report released to The Seattle Times did not comment on the question of potential negligence.
It concludes that the fire was caused by branches of a water birch tree rubbing up against the power line and noted that all other potential sources of ignition were considered but excluded. Investigators say that branches began burning without an interruption of electrical service.
The Seattle Times late Friday afternoon was unable to contact Okanogan County Electrical Cooperative officials for comment on the report. The utility’s website describes the cooperative as a nonprofit run by a board elected by members.
In a statement to state investigators, a utility official said the power lines are maintained to standards, with trees removed typically every three years, or whenever it’s deemed necessary. In the area where the fire broke out, the lines were last cleared during the winter of 2012-13.
The Twisp fire began on a parched summer day and was first reported to authorities at 12:23 p.m. by a homeowner.
“I happened to look out my window, and there was a big column of smoke below my house,” Martha Tazioli, a part-time resident of the Methow Valley who lives on Woods Canyon Road, said Friday.
By 2:45 p.m., as fire crews were on scene, the winds had escalated and shifted from the fire’s left flank to its right, causing extreme flame behavior that generated intense smoke, according to an earlier joint federal and state report released in November.
“The wind had shifted and increased (the fire’s) speed,” that report says. “Correspondingly, extreme fire behavior was observed, which astounded even the most experienced firefighters at Twisp.”
The three firefighters perished after their engine ran off the road as they tried to drive down the winding Woods Canyon Road as they were blinded by smoke. The fourth firefighter, Lyon, though badly burned, managed to stagger away from the truck.
Though many of the large fires in 2015 were sparked by lightning, historically about 85 percent of all wildfires in the state each year are human-caused, according to the state Department of Natural Resources.
Nationwide, power lines also often cause fires.
In Texas, more than 4,000 fires were caused by power lines over a 3 ½ -year period, costing the state and residents hundreds of millions of dollars, according to research cited by the Texas A & M Engineering Experiment Station, which is involved in a project to try to reduce the risks of such fires.
Hal Bernton: 206-464-2581 or [email protected]
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