FILE - In this Sept. 11, 2010, file photo, a natural gas line lies broken on a San Bruno, Calif., road after a massive explosion. The California Public Utilities Commission said Friday, Dec. 14, 2018, that an investigation by its staff found Pacific Gas & Electric Co. lacked enough employees to fulfill requests to find and mark natural gas pipelines. A U.S. judge fined the utility $3 million after it was convicted of six felony charges for failing to properly maintain a natural gas pipeline that exploded south of San Francisco in 2010, killing eight people. (AP Photo/Noah Berger, File)

SAN FRANCISCO - Regulators on Friday accused one of California's largest utilities of falsifying safety documents for natural gas pipelines for years following its criminal conviction and multimillion-dollar fine for a pipeline explosion that killed eight people near San Francisco.

The California Public Utilities Commission said an investigation by its safety and enforcement division found Pacific Gas & Electric Co. lacked enough employees to fulfil requests to find and mark natural gas pipelines.

Because of the staff shortage, PG&E pressured supervisors and locators to complete the work, leading staff to falsify data from 2012 to 2017, regulators said. The company "had common knowledge among its supervisors that locators falsified data," the commission said.

"Utility falsification of safety related records is a serious violation of law and diminishes our trust in the utility's reports on their progress," commission President Michael Picker said in a statement. "These findings are another example of why we are investigating PG&E's safety culture."

PG&E said it has hired more employees and improved its pipeline tracking system.

"We're committed to accurate and thorough reporting and record-keeping, and we didn't live up to that commitment in this case," utility spokesman Matt Nauman said in a statement.

A U.S. judge fined the utility $3 million after it was convicted of six felony charges for failing to properly maintain a natural gas pipeline that exploded in 2010 and wiped out a neighbourhood in suburban San Bruno. Regulators also fined PG&E $1.6 billion for the blast.

"This is the period immediately following the 2010 San Bruno gas explosion and fire that resulted in eight fatalities, numerous injuries and damage to property," the commission said in its report. "This commission would expect that after such a tragedy, caused by multiple proven violations of law, PG&E would have sought to vigorously enhance and increase its effectiveness in all aspects of its gas safety."

The investigation was forwarded Thursday to a judge, who will hear testimony on the findings and will allow PG&E to provide evidence that it didn't violate safety laws.

The utility that provides service to millions of people throughout Northern California also is under scrutiny for its role in igniting wildfires. The California Department of Forestry and Fire Protection found that PG&E equipment was responsible for starting 16 wildfires last year.

While a cause has not yet been determined for the massive fire that wiped out the town of Paradise and killed at least 86 people last month, PG&E equipment is being scrutinized. A number of victims have sued the utility, alleging negligence.

News from © The Associated Press, 2018