The utility company that services more than a third of California announced on Monday it plans to file for bankruptcy by the end of the month. Several deadly wildfires believed to have been caused by the company left it with potential liabilities of at least $30bn.

The board of directors of Pacific Gas and Electric (PG&E) has determined that the move “is ultimately the only viable option to restore PG&E’s financial stability to fund ongoing operations and provide safe service to customers”, the San Francisco-based company stated in a filing at the Security and Exchange Commission.

PG&E, which provides gas and electricity to 16 million Californians, is under investigation for its role in November’s Camp fire, the deadliest wildfire in the state’s history.

The company has been found responsible for several other disasters in recent years, including the 2017 North Bay fires, which killed 43 people and destroyed more than 14,700 homes, the 2015 Butte fire, which killed two people and destroyed almost 900 structures, and a a 2010 gas line explosion in San Bruno that ripped through an entire neighborhood, killing eight and injuring 58 people. PG&E was fined $1.6bn for the San Bruno explosion and a federal jury found the company guilty of six felony charges, ordering it to pay $3m in fines.

PG&E’s chief executive, Geisha Williams, has resigned. Photograph: Marcio José Sánchez/AP

With Monday’s announcement, PG&E hopes to reach a resolution for potential liabilities resulting from the Camp fire and the North Bay fires.

“We believe a court-supervised process under Chapter 11 will best enable PG&E to resolve its potential liabilities in an orderly, fair and expeditious fashion,” the interim PG&E CEO, John Simon, said in a statement. “We expect this process also will enable PG&E to access the capital and resources we need to continue providing our customers with safe service and investing in our systems and infrastructure.”

Monday’s moves come during a period of intense disruption for the company. S&P Global Ratings and Moody’s Investors Services cut PG&E’s credit grades to junk status, down from investment-grade level, last week. The federal judge overseeing the utility after the 2010 San Bruno explosion also moved to order the company to reinspect its grid and “remove or trim all trees” that could fall on power lines ahead of next year’s fire season. And on Sunday, PG&E’s chief executive, Geisha Williams, announced her resignation. Williams is set to receive a severance payment of about $2.5m, as well as accrued pension benefits, “the same as any employee of the company”, said Matt Nauman, a PG&E spokesman.

California’s governor, Gavin Newsom, who was elected just days before the Camp fire ignited, said in a statement on Monday that he has been “closely monitoring the impact of PG&E’s existing and potential future liability”, but would not go into detail about any possible government intervention.

“Everyone’s immediate focus is, rightfully, on ensuring Californians have continuous, reliable and safe electric and gas service,” Newsom said. “While PG&E announced its intent to file bankruptcy today, the company should continue to honor promises made to energy suppliers and to our community.

Last fall, the then governor, Jerry Brown, signed into law a bill allowing utility companies whose equipment is found to have caused a wildfire to increase rates over several years in order to pay for liability costs. Consumer watchdog groups strongly opposed the law, knowing that under it, any wildfires from 2017 on could be covered in such fashion.

Pacific Gas & Electric vehicles in Oakland, California. Photograph: Ben Margot/AP

“Basically, from our perspective, customers pay a bill every month and they pay it because they want to have safe and reliable electricity and that is where our money should be going toward,” said Mindy Spatt, a spokeswoman for the Utility Reform Network. “Customers can’t afford to keep paying for PG&E’s negligence and liabilities.”

In a statement on Monday, the San Francisco city attorney, Dennis Herrera, vowed to “vigorously defend” the interests of San Francisco taxpayers and hold PG&E to its promise that “the power stays on during the company’s financial turmoil”.

“We will also remain vigilant,” Herrera said. “PG&E should not be allowed to shift its failures onto the backs of hardworking residents. We are working with other policymakers to ensure that this situation results in safe, reliable, clean and affordable power for ratepayers, including the possibility of a publicly owned utility.”