It’s a question worth billions of dollars: How did California’s most destructive wildfire start?
One year after the Tubbs fire burst from a spark and became a wind-driven inferno, thousands of people who lost homes as well as relatives of the 22 people killed are still waiting to learn what caused the wildfire that upended their lives.
Cal Fire has concluded PG&E power lines and equipment sparked 16 of the 18 fires that broke out Oct. 8 and 9 across Northern California. Investigators handed reports for 11 of those fires — including the Atlas fire that killed six people in Napa County — to local prosecutors, who will review evidence asserting the utility company hadn’t followed safety laws and was criminally negligent.
But the agency has not yet revealed the results of its investigation into the Tubbs fire, which burned 36,807 acres from Calistoga west over the Mayacamas Mountains, destroying entire Santa Rosa neighborhoods and causing nearly $8 billion in insured losses in Sonoma County.
The only other pending fire investigation from October 2017 is for the 10,000-acre Cascade fire in Yuba County, and that report is expected to be announced within the next week, according to Cal Fire spokesman Scott McLean.
Investigation began immediately
The high-stakes investigation into the Tubbs fire has no timeline, McLean said.
Its conclusions have major consequences for PG&E, which is already anticipating up to $17 billion in potential liabilities from the 2017 fires. The investigation will impact hundreds of people who are suing the San Francisco-based utility in anticipation that its power equipment led to the initial spark.
“There is a lot riding on those fires,” said veteran fire investigator Dan White, a Redding-based division chief in Cal Fire’s fire prevention and law enforcement division. “They were extremely devastating. People lost their homes and lost their lives. Sometimes with fires like that, it takes longer.”
When the first firefighters raced toward the wind-whipped fires that broke out a year ago across the North Bay, an army of state fire investigators also fanned out, identifying early on the suspected origins of the blazes.
Working parallel to fire crews, inspectors recorded clues from the way the fires burned and the scorched evidence was left behind — the first phase of what became monthslong examinations into the deadliest and most destructive siege of wildfire ever in California.
Power equipment suspected
The Tubbs fire ignited about 9:45 p.m. Oct. 8 at rural residential property on Bennett Lane north of Calistoga in the northern end of Napa Valley. It quickly spread west, raging in hot and dry conditions, driven by fierce winds.
Cal Fire investigators seized as evidence damaged power equipment from a property near the fire’s origin, according to state regulators. For weeks after the Tubbs fire started, private security guards and yellow crime scene tape barred entry to two Bennett Lane driveways leading up to the side of a wooded hill overlooking vineyards.
PG&E has asserted it may have been a private power line “owned, installed and maintained by a third party,” and not the utility’s equipment that started the Tubbs fire, according to court documents filed by lawyers representing the utility giant against a mounting number of civil lawsuits alleging the company was negligent in its care of the power grid.
Cal Fire findings on 16 Northern California wildfires
Redwood fire (Mendocino County): 543 structures destroyed, 9 deaths, 36,523 acres burned. The fires started in two locations when trees or tree parts fell onto PG&E power lines.
Nuns, Norrbom, Adobe, Partrick & Pythian fires (Sonoma and Napa counties): 1,355 structures destroyed; 3 deaths, 56,556 acres burned (Sonoma and Napa counties); all but Nuns fire referred to District Attorney.
• Nuns: Broken top of a tree crashed into power lines.
• Norrbom: Tree fell onto power lines.
• Adobe: Tree fell into PG&E power line.
• Partrick: Oak tree fell into PG&E power lines.
• Pythian: The fire started with a downed power line caused after PG&E tried to re-energize the line.
Atlas fire (Napa County): 783 structures burned, 51,624 acres burned, 6 deaths; referred to the District Attorney. The fire started Oct. 8 in two locations when a large limb broke from a tree and came into contact with PG&E power lines and a tree fell onto the same line.
Sulphur fire (Lake County): 2,207 acres, 162 structures destroyed; referred to the District Attorney. Fire ignited when a PG&E power pole failed, causing power lines and equipment to contact the ground.
Pocket fire (Sonoma County): 6 structures destroyed, 17,357 acres burned; referred to the District Attorney.
37 fire (Sonoma County): 3 structures destroyed, 1,660 acres burned (Sonoma County). PG&E distribution lines started an electrical fire.
Blue fire (Humboldt County): 20 acres burned; referred to the District Attorney. A PG&E power line conductor separated from a connector, causing the conductor to fall to the ground and start a fire.
Cherokee fire (Butte County): 6 structures destroyed, 8,417 acres burned. Fire started when tree limbs made contact with PG&E power lines.
La Porte fire (Butte County): 6,151 acres burned and 74 structures destroyed. Fire started early Oct. 9 when tree branches fell into PG&E power lines. Investigators found no state law violations.
McCourtney fire (Nevada County): 76 acres burned; 13 structures destroyed; referred to the District Attorney. Fire started Oct. 8 when tree fell into PG&E power lines. Investigators determined PG&E failed to remove a tree too close to a power line.
Lobo fire (Nevada County): 821 acres burned; 47 structures destroyed; referred to the District Attorney. Fire started Oct. 8, caused by a tree contacting PG&E power lines. Investigators found PG&E failed to ensure adequate clearance between trees and power lines.
Honey fire (Butte County): 76 acres burned; referred to the District Attorney. Fire started Oct. 9 when an oak branch contacted PG&E power lines. Investigators found PG&E failed to ensure adequate clearance between trees and power lines.
*Those cases referred to the District Attorney indicate Cal Fire determined PG&E was in violation of state codes, most related to clearing tress and other vegetation from power lines.