Determining that one of the October 2017 fires that devastated the state's wine-making region resulted from a Pacific Gas and Electric Co. power line, California fire investigators concluded that the utility did not violate any law.

The Cascade Fire in Yuba County, Calif., started on Oct. 8, 2017, when high winds slapped two sagging lines together, creating an electrical arc that caused burning or molten material to fall onto combustible material on the ground, the California Department of Forestry and Fire Protection, or CAL FIRE, found. In June CAL FIRE released conclusions that it had found evidence of alleged violations of state law involving eight of the 12 wildfires in PG&E's Northern California service territory it was investigating.

The October 2017 blazes involved more than 170 fires that burned at least 245,000 acres and resulted in 44 deaths and billions of dollars in property damage. The Cascade fire alone killed four people and injured a firefighter, destroying 264 structures and burned 9,989 acres.

CAL FIRE investigators are still trying to pinpoint the cause of the deadliest of the October fires, the Tubbs Fire in Sonoma County, which killed 22 people, destroying 5,636 structures and burning 36,807 acres. PG&E and its investors are anxiously awaiting the outcome of that investigation.

Responding to the Cascade Fire report, the PG&E Corp. subsidiary issued a press release emphasizing multiple precautions it is taking to reduce wildfire threats. The utility said it is removing or pruning 1.4 million trees annually near its lines, making lines and poles stronger, inspecting power lines, notifying customers of fire safety hazards, and turning off electric power when dangerous fire conditions occur.