PG&E equipment was implicated in two of the biggest, deadliest fires that swept through Northern California last October, Cal Fire said Friday: The Redwood Fire in Mendocino County, which killed nine people, and the Atlas Fire in Napa County, which killed six.

In the case of the Atlas Fire, as well as seven others, the state fire agency said that PG&E may have violated state law and referred the case to local prosecutors for review.

In all, Cal Fire released its findings Friday on 12 of the more than 170 fires starting last Oct. 8 as hot, dry winds roared through much of Northern California. The agency’s investigators found that all but one were connected to PG&E electrical lines, power poles or other equipment. In the lone case where PG&E was not cited, a power line was also the cause, but Cal Fire did not immediately say who owns that line.

The cause has not yet been announced for the blaze that caused the greatest loss of life and the most extensive property damage — the Tubbs Fire, which ignited near Calistoga and raced across the hills into Santa Rosa. That blaze killed 22 people and destroyed more than 5,000 homes.

State Sen. Jerry Hill, D-San Mateo, said the findings — combined with investigations released two weeks ago blaming PG&E for four other fires — refutes the utility’s recent arguments that a “new normal” created by climate change is to blame for such devastating disasters.

“It doesn’t come as a big surprise, but I think we have to be clear … these fires are not started by a new normal. They are caused by negligence by PG&E,” Hill said.

The Cal Fire findings raise questions about the future of PG&E, the state’s largest utility. But in a statement, PG&E repeated its assertion that “years of drought, extreme heat and 129 million dead trees have created a ‘new normal’ for our state that requires comprehensive new solutions.”

“Extreme weather is increasing the number of large wildfires and the length of the wildfire season in California,” the statement said. “The loss of life, homes and businesses in these extraordinary wildfires is simply heartbreaking, and we remain focused on helping communities recover and rebuild. We look forward to the opportunity to carefully review the Cal Fire reports to understand the agency’s perspectives. Based on the information we have so far, we continue to believe our overall programs met our state’s high standards.”

But John Fiske, a lawyer for the counties of Mendocino, Napa and Sonoma in their litigation against PG&E, said Friday’s findings prove the opposite.

“Today, Cal Fire confirmed what we’ve known, that PG&E has systemic management deficiencies that fail to recognize the serious nature of wildfire prevention,” he said in a statement. “So far, 16 of 16 North Bay fires have been found caused by PG&E, 11 of which have been referred to District Attorneys. It is time for the executives at PG&E to get serious about rebuilding these communities and preventing further disasters.”

Fiske blamed PG&E for all 16 fires investigated so far, but in one case — the Nuns Fire — Cal Fire said it was a power line, but didn¹t specify who owns that line.

Here’s the fire agency’s summary of the dozen determinations announced Friday:

• The Redwood Fire, in Mendocino County, started the evening of Oct. 8 and burned a total of 36,523 acres, destroying 543 structures. There were nine civilian fatalities and no injuries to firefighters. Cal Fire has determined the fire started in two locations and was caused by trees or parts of trees falling onto PG&E power lines.
• The Atlas Fire, in Napa County, started the evening of Oct. 8 and burned a total of 51,624 acres, destroying 783 structures. There were six civilian fatalities. Cal Fire investigators determined the fire started in two locations. At one location, it was determined a large limb broke from a tree and came into contact with a PG&E power line. At the second location, investigators determined a tree fell into the same line.
• The Norrbom, Adobe, Partrick, Pythian and Nuns fires were part of a series of fires that merged in Sonoma and Napa counties. These fires started in the late-night hours of Oct. 8 and burned a combined total of 56,556 acres, destroying 1,355 structures. There were three civilian fatalities. Cal Fire said four of five of those fires were connected to PG&E equipment. The Nuns Fire was said to have been caused by the broken top of a tree coming into contact with a power line, but PG&E was not named.
• The Sulphur Fire, in Lake County, started the evening of Oct. 8 and burned a total of 2,207 acres, destroying 162 structures. There were no injuries. Cal Fire investigators determined the fire was caused by the failure of a PG&E-owned power pole, resulting in power lines and equipment coming in contact with the ground.
• The Cherokee Fire, in Butte County, started the evening of Oct. 8 and burned a total of 8,417 acres, destroying six structures. There were no injuries. Cal Fire investigators have determined the cause of the fire was a result of tree limbs coming into contact with PG&E power lines.
• The 37 Fire, in Sonoma County, started the evening of Oct. 9 and burned a total of 1,660 acres, destroying three structures. There were no injuries. Cal Fire investigators have determined the cause of the fire was electrical and was associated with the PG&E distribution lines in the area.
• The Blue Fire, in Humboldt County, started the afternoon of Oct. 8 and burned a total of 20 acres. There were no injuries. Cal Fire investigators have determined a PG&E power line conductor separated from a connector, causing the conductor to fall to the ground, starting the fire.
• The Pocket Fire, in Sonoma County, started the early morning hours of Oct. 9 and burned a total of 17,357 acres, destroying 6 structures. There were no injuries. Cal Fire has determined the fire was caused by the top of an oak tree breaking and coming into contact with PG&E power lines.

Cal Fire will hand over its findings to the California Public Utilities Commission, which regulates electric and gas utilities in California. The CPUC will be charged with determining if PG&E was out of compliance with CPUC rules and regulations and should be subject to fines and other action.

There will also be criminal investigations into the company’s actions before the fires.

Bill Brockley, an assistant district attorney in Sonoma County, said the criminal investigations into the fires are sprawling, and Sonoma County prosecutors are coordinating with Napa and Lake counties and the state Attorney General’s Office.

“This is the first fire that I’ve ever had an experience with that’s this size,” Brockley said. “Some of the fires started and ended in different counties, so that’s why we’re all working together and coordinating our efforts.”

CPUC said its investigations into PG&E’s role in the fires is ongoing and could result in extensive penalties.

Regardless of future determinations by the CPUC and law enforcement, civil lawsuits, insurance claims and political fallout all also pose major financial threats to PG&E.

The utility is facing more than 100 suits from fire survivors and government agencies blaming it for the blazes. Insurance claims for the fire are around $10 billion, more than 10 times the amount of liability insurance that PG&E carries.

One of the attorneys litigating the cases against the utility says monetary penalties are just part of the remedy he seeks.

Frank Pitre, co-counsel in 150 lawsuits, said Cal Fire’s report is “an indictment of the failure of PG&E’s risk management practices.”

“You need a team of experts to go in and make recommendations on how to change the culture at PG&E so the same thing doesn’t happen again,” Pitre said. “That’s what I want.”

There’s also a battle going on in Sacramento over whether lawmakers should change a long-standing state law that allows a utility to be held financially responsible for damage it causes — even if it complied with state regulations. PG&E executives have been vocal about their desire to amend that law, arguing that climate change has altered the risks inherent in the utility industry and that holding the company liable could force it out of business.

Hill, the state senator, has threatened to push legislation that would break up PG&E. He said Friday that the option remains “on the table.”

Hill has been a fierce critic of PG&E since the utility’s gas lines blew up a neighborhood in his Bay Area district in 2010, killing eight people and leveling 38 homes. Subsequent investigations, including by federal regulators, revealed that the explosion was the result of PG&E’s inadequate maintenance and record keeping and that state regulators at the CPUC hadn’t properly supervised the utility. PG&E was ultimately convicted of six felony counts, and paid more than $1 billion in fines, lawsuit settlements and refunds to customers.

Last month, Cal Fire determined that four fires in Butte and Nevada counties that were part of the same fire siege were caused by PG&E equipment. In three of those blazes, Cal Fire said, the utility may have violated state law; the cases were referred to local prosecutors for review.