(UPDATED at 6:20 p.m. PDT October 9, 2018)
Investigators looking into the cause and origin of the large wildfires that plagued Northern California last fall have determined that a Pacific Gas and Electric power line started the Cascade Fire in Yuba County. The blaze started on the evening of October 8 and burned a total of 9,989 acres, destroyed 264 structures, and resulted in four civilian fatalities and one firefighter injury.
“A high wind event in conjunction with the power line sag on two conductors caused the lines to come into contact, which created an electrical arc”, the California Department of Forestry and Fire Protection (CAL FIRE) said in a news release. “The electrical arc deposited hot burning or molten material onto the ground in a receptive fuel bed causing the fire. The common term for this situation is called ‘line slap’ and the power line in question was owned by the Pacific Gas and Electric Company.”
The investigative report for the Cascade Fire was forwarded to the Yuba County District Attorney, which is the usual practice. The D.A. decided that no violations of the Public Utilities Code in regard to vegetation management were found and made no other recommendations regarding criminal action, including the offense of involuntary manslaughter.
In total, the October 2017 Fire Siege involved more than 170 fires and burned at least 245,000 acres in Northern California. Approximately 11,000 firefighters from 17 states and Australia helped battle the blazes.
Earlier CAL FIRE said an additional 16 fires during the siege were attributed to PG&E equipment, alleging violations of state law in 11 of those incidents. CAL FIRE still hasn’t released its report on the Tubbs blaze, the deadliest of last year’s fires, which killed 22 people, destroyed 5,643 structures, and burned 36,807 acres.
In a news release PG&E addressed the CAL FIRE report about the Cascade Fire:
We look forward to the opportunity to carefully review the CAL FIRE report to understand the agency’s perspectives.
The safety of our customers, their families and the communities we serve is our most important job. Without question, the loss of life, homes and businesses in these extraordinary wildfires is heartbreaking and we remain focused on helping communities recover and rebuild.
In the meantime, we are continuing to focus on implementing additional precautionary measures intended to further reduce wildfire threats, such as working to remove and reduce dangerous vegetation, improving weather forecasting, upgrading emergency response warnings, making lines and poles stronger in high fire threat areas and taking other actions to make our system, and our customers and communities, even safer in the face of a growing wildfire threat.
This article was updated to include a response from PG&E.