SAN FRANCISCO (AP) — The California agency investigating the deadly 2010 gas pipeline explosion in a San Francisco Bay Area neighborhood recommended Monday that Pacific Gas & Electric Co. pay a $2.25 billion fine for its negligence leading up to the blast.

The penalty would be the largest ever assessed by a state regulator, officials said.

READ MORE: 'He Had To Watch... As This Monster Did What He Did': Sacramento Family Of Texas Shooting Survivor Speaks

The California Public Utilities Commission recommended the fine and said the company’s shareholders should shoulder it, not the utility’s customers.

The blast in San Bruno sparked a fireball that killed eight people, injured dozens more and destroyed 38 homes in the quiet bedroom community.

Commission investigators and consumer advocates filed a range of proposals for fines Monday.

The City of San Bruno, which is still struggling to rebuild the neighborhood devastated in the blast, said earlier Monday that the utility’s shareholders should pay no less than $1.25 billion in fines, plus at least $1 billion toward pipeline inspection and upgrade costs.

PG&E will file its proposal later this month, and a judge from the utilities commission is expected to make a final decision about how much to fine PG&E later this year.

READ MORE: Man Found In Car Intoxicated, Arrested For DUI In Lodi

Consumer advocates said the fine the commission proposed was appropriate, given the company’s myriad violations before the blast. The proposal calls for all the money to be directly invested in safety testing, replacing and upgrading hundreds of miles of PG&E’s gas transmission lines, rather than being sent to the state’s general fund.

“It’s absolutely the amount PG&E should pay for their all their past violations,” said Marcel Hawiger, an attorney with the nonprofit Utility Reform Network. “This is a very big penalty, but it’s not quite as big as it seems when you account for the tax benefits PG&E would accrue.”

The National Transportation Safety Board unanimously agreed in 2011 that the accident was caused by what board chairman Deborah Hersman called a “litany of failures” by PG&E, as well as weak oversight by regulators.

Separate from the NTSB investigation, state investigators at the California Public Utilities Commission have blamed PG&E for the explosion, which occurred when an underground pipeline ruptured at the site of a decades-old faulty weld, sparking a gas-fueled fire.

MORE NEWS: Man Arrested After Running Stop Sign Then Fleeing From Police

Copyright 2013 The Associated Press.