As the California Dept. of Forestry and Fire Protection (Cal Fire) struggles to contain one of the deadliest fires to hit the West Coast in 100 years, investigators are moving to preserve evidence in the search for the cause of the blazes in the wine-making counties of Sonoma and Napa, including possible link to power lines.

More than 40 people have been killed, and about 5,700 structures have been destroyed.

In a report to the U.S  Securities and Exchange Commission released Oct. 13, Pacific Gas & Electric Co. said, “The causes of these fires are being investigated … including the possible role of power lines. It currently is unknown whether the utility would have any liability associated with these fires.”

The utility has $800 million in liability insurance for potential losses that may result from these fires, PG&E executives noted.