SAN FRANCISCO (Reuters) - California regulators have ordered utility PG&E Corp to inspect its natural gas pipeline system following an explosion that destroyed a neighborhood in a San Francisco suburb last week, killing four people.
The California Public Utilities Commission (CPUC) asked PG&E to immediately conduct an integrity assessment of its natural gas pipeline system.
The regulators want the utility to survey all natural gas lines, particularly those that carry gas at higher pressure and those in areas of highest population density.
CPUC is also appointing an independent panel of experts to help its investigation into the blast.
In addition to killing four, the blast, caused by a ruptured natural gas pipeline, and ensuing firestorm destroyed 37 homes and injured more than 50 people in San Bruno.
The 30-inch (76-cm) steel gas transmission pipeline belongs to PG&E, which has set up a $100 million fund to help the residents and city of San Bruno.
The company has said it is still looking into why the pipeline ruptured. It said it is working quickly to examine other lines to ensure that they are safe.
The section of the gas line was installed around 1956.
PG&E has a network that includes 42,141 miles of natural gas distribution pipeline and 6,438 milesof transmission, or high pressure, pipeline. The whole network serves 4.3 million customers, a spokeswoman said.
PG&E said it will provide immediate disbursements of between $15,000 to $50,000 per household to those affected by the blast.
Investigators from the National Transportation Safety Board have already begun a probe into the cause of the blast.
Shares of PG&E closed up 5 cents at $44.26 on the New York Stock Exchange.
(Reporting by Poornima Gupta; Editing by Cynthia Osterman)