The National Transportation Safety Board heard testimony from officials at Pacific Gas & Electric regarding a September natural gas pipeline explosion in San Bruno.
The company in a memo said it didn't use an automated shutoff valve on the San Bruno line. The Wall Street Journal quoted the PG&E memo as saying that the company only supported the use of the automatic valves for "specific conditions such as bridge crossings, river crossings, earthquake fault crossings, etc."
The NTSB found the San Bruno pipeline crosses the San Andreas Fault twice.
The fire raged in the San Bruno neighborhood for more than an hour. PG&E had to manually close pipeline valves so firefighters could reach the blaze.
Federal regulators only recommend, not require, that utility companies use automated shutoff valves. California lawmakers are proposing measures that would require such precautions, something the Journal noted PG&E supports.
The NTSB inquiry is the first since 2000. The San Bruno gas explosion killed eight people and destroyed 38 homes.