The state Public Utilities Commission unanimously approved a $2 million utility-financed wide-ranging investigation to gauge Pacific Gas and Electric Co.’s emphasis on safety in the aftermath of the San Bruno gas explosion. The panel previously imposed a historic $1.6 billion penalty for the Sept. 9, 2010, blast that killed eight people. Now the company’s string of post-San Bruno regulatory troubles suggested that utility was simply too big to regulate and might need to be broken up.

The investigation will amount to a deeper review of the companies organizational culture, governance, and operations, and the systemic issues identified by the National Transportation Safety Board. The safety board blames the 2010 explosion largely on PG & E’s “organizational failure” and lax safety leading up to the event. The safety arm of the commission will now work with an outside consultant to draft a report that will be reviewed by an administrative law judge in charge of the proceeding.

Meanwhile, the Los Angeles Times reports that the Public Utilities Commission itself — beset by criticism that its officials have a too-cozy relationship with the utilities they regulate — failed to respond to a search warrant for records related the California attorney general’s investigation of agency operations. A court document filed Aug. 7 states that “after multiple requests, and two months after the search warrant was served on CPUC, no records have been produced.” Special Agent Reye Diaz of the attorney general’s office added: “No extension has been requested and no indication has been given as to when the records will be produced.”

The attorney general is investigating secret talks between the commission and Southern California Edison, the state’s second largest investor-owned utility, that led to decisions that are costing utility customers billions of dollars.