Pacific Gas and Electric Corp. CEO Bill Johnson stood before a judge in Chico, Calif., Tuesday and replied “guilty, your honor,” 84 times to charges of involuntary manslaughter as he watched photographs of those who died in the 2018 Camp Fire display on a courtroom screen.

One of largest corporate homicide cases in U.S. history is scheduled to conclude Friday, when Butte County Superior Court Judge Michael Deems sentences PG&E on the manslaughter charges and one count of starting an illegal fire. The November 2018 Camp Fire was the deadliest and most destructive wildfire in state history.

A plea deal calls for PG&E to pay the maximum fine of nearly $4 million. It is already on probation for six felony counts stemming from the San Bruno gas pipeline explosion in September 2010.

The company also plans to pay $13.5 billion to victims of the Camp Fire and a series of Northern California fires in October 2017 when it exits bankruptcy, probably within the next two weeks. (See Lawyers Close PG&E Bankruptcy Case.)

Those who lost family members and homes in the fire will have Wednesday, Thursday and part of Friday to address the court prior to sentencing.

Johnson expressed remorse on behalf of PG&E Tuesday and vowed the company would change.

“Our equipment started the fire that destroyed the towns of Paradise and Concow and severely burned Magalia and other parts of Butte County,” Johnson told the judge. “That fire took the lives of 85 people. Thousands lost their homes and businesses, and many others were forced to evacuate under horrific circumstances. I wish there were some way to take back what happened or take away the pain of those who’ve suffered. But I know there’s not.”

Prosecutors said one of the 85 who died committed suicide as flames approached, but they lacked evidence to prove he killed himself to avoid being killed by the fire.

Butte County District Attorney Michael Ramsey released a report Tuesday listing the names and ages of the dead. They included 99-year-old Rose Farrell, who was found on her front porch in Paradise near her empty wheelchair. Five others who died were women in their 90s; a dozen other victims were in their 80s.

Matilde Heffern, 68, her daughter Christina Heffern, 40, and granddaughter, Ishka Heffern, 20, died together in their home as it burned.

“Their remains were located commingled in the bathtub of their residence,” the prosecutor’s report said. “The Hefferns placed a 911 call as the fire approached their home. Somehow the phone line remained open as the house, and the three women, burned as helpless [emergency] dispatchers listened to their screams.”

Others perished in their vehicles, overcome by smoke and flames, as they tried to flee. A firefighter was “horribly burned” helping his fellow firefighters escape to safety, the district attorney said.

Ramsey said the cause of so much suffering and death was a 100-year-old broken C hook on a PG&E transmission line. The part cost less than a dollar when it was manufactured in 1919 and sells for about $13 today, he said.

“That is what killed 84 Butte County citizens,” Ramsey said, holding up the broken hook at a press conference following the arraignment.

‘Negligent and Reckless’

The report by Ramsey’s office examined in detail the decades of inspection and maintenance failures by PG&E that led to the C hook breaking. The report relied on investigations by the California Department of Forestry and Fire Protection (Cal Fire), the FBI and PG&E testimony before a grand jury.

The company skimped on inspections and upgrades for years to cut costs and boost profits, the report said. In 2013 it formed a committee to “explore opportunities to reduce costs by reducing the frequency of inspections and patrols” and gave bonuses to transmission line superintendents and supervisors based partly on staying under budgets, it said.

“As expected, the result of these reductions was less thorough and less complete inspections and patrols,” the report said.

The lax inspections and poor maintenance compounded problems on PG&E’s aging infrastructure, including the century-old Caribou-Palermo line, where the Camp Fire started.

“The fact that PG&E relied on a … 100-year-old C hook it knew nothing about to hold an energized 115-kV conductor is, by itself, negligent and reckless,” the report said.

PG&E likely knew the hardware was aging because sometime in the past its crews had replaced worn hanger plates on the line’s transmission towers, and a 1986 inspection of a similarly aged PG&E line had found worn C hooks, it said.

The Caribou-Palermo line was built between 1919 and 1921 by the Great Western Power Co., which PG&E bought in 1930. The line, now shut down, connected hydroelectric stations in the steep Feather River Canyon to population centers in the San Francisco Bay area. It crossed rugged foothills where winds gusted to more than 50 mph.

“Despite the fact that PG&E has owned … the Caribou-Palermo line since 1930, the evidence established PG&E did not catalogue or replace the original conductors, insulators or attachment hardware on many of the towers,” the report said.

In December 2012, five towers on the line collapsed, and a sixth was badly damaged in a domino effect that likely started when one tower’s “stub angles,” which connected the tower to its base, broke due to high winds and wet, icy ground, a PG&E engineer concluded. The engineer recommended inspections on other towers, but PG&E didn’t follow through, the report said.

“Again, this is consistent with PG&E’s practice of not following up on clearly established potential safety and/or maintenance issues,” it said.

The conductor on the Caribou-Palermo line was aluminum reinforced with a steel core, which has a lifespan of 36 years and carries a high risk of failure, according to a report by Quanta Technologies, a consultant PG&E hired in 2009 to assess its transmission system.

“What it says is that PG&E fully intended to run that conductor to failure,” the prosecutors’ report concluded. “A reasonable person doesn’t need an electrical engineer or Quanta Technologies to tell him that failure of an energized 115-kV [line] is extremely dangerous. PG&E’s decision to leave the 97-year-old aluminum, steel-reinforced conductor in service was extraordinarily reckless.”

“In essence, in 1930, PG&E blindly bought a used car. PG&E drove that car until it fell apart,” starting the Camp Fire, the report said.