NTSB Finds No External Corrosion In San Bruno Gas Pipe Blast

SAN BRUNO (AP) – A gas pipeline that ruptured and caused the deadly San Bruno explosion showed no signs of corrosion and wasn’t dented or leaking, federal accident investigators said Tuesday.

The National Transportation Safety Board has yet to determine what caused the transmission line to rupture on Sept. 9, killing eight people and destroying dozens of homes.

KCBS’ Holly Quan Reports:

Investigators found no physical evidence of a pre-existing leak in the pipe pieces, nor did they see dents or gouges suggesting that someone struck the pipe with excavation equipment.

But the report did confirm that the 30-inch pipe was riddled with welding seams, in contrast to previous claims by the ruptured pipeline’s operator, Pacific Gas & Electric, that the pipe was seamless.

“They didn’t know what they had under the ground in this location,” Rep. Jackie Speier, a California Democrat who represents the San Bruno area, said at a news conference Tuesday. “It troubles me greatly and I think this is one of the issues we have to address swiftly.”

Speier said she planned to ask federal pipeline safety regulators to probe whether it was legal for PG&E to have inspected the 1956 pipeline without using the most high-tech methods available, such as sending a robot into the pipe.

Company officials have acknowledged that the utility has yet to fully inspect all its high-risk gas lines coursing through the most densely populated regions of the state.

The explosion and ensuing inferno torched nearly 15 acres of 1960s-era suburban homes in the hills overlooking the San Francisco Bay. Dozens of people were injured in the blast, and some victims are still in hospital burn units.

PG&E called the pipe “high-risk” in 2007 and received permission from the California Public Utilities Commission to bill ratepayers to upgrade the pipeline. But they dropped the improvement plans the next year.

The NTSB also is investigating why it took PG&E crews nearly 90 minutes to deploy manual valves to stop the flow of gas into San Bruno the night of the explosion. NTSB findings issued thus far are preliminary and a final report is not likely to come out for months, Speier said.

“This report is a snapshot in time, but we don’t have a cause yet,” San Bruno Mayor Jim Ruane said Tuesday. “It’s going to take a lot longer to rebuild our community.”

(© 2010 CBS Broadcasting Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)


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