From The Los Angeles Times: The National Transportation Safety Board also said PG&E exploited the lack of monitoring by regulators, who mistakenly placed "blind trust" in the utility. San Bruno pipeline explosion: 'A failure of the entire system' - latimes.com
The New York Times also reported: The main cause of the pipeline rupture that killed eight people and burned three dozen houses last September was 54 years of bad management by Pacific Gas & Electric Company, and state and federal regulators who did not notice the problem, the National Transportation Safety Board said on Tuesday.
PG&E Mismanagement Blamed for San Bruno Gas Disaster - NYTimes.com