Washington, D.C. — Nearly a year after a natural gas pipeline blew up a San Bruno neighborhood and ended eight lives, federal investigators will reveal what they believe caused the explosion.
The results of the investigation will be made public in a hearing today. Survivors of the blast, San Mateo County prosecutors and pipeline operator PG&E will be paying close attention to investigators’ conclusions, since they may clarify how much responsibility the energy company bears for the deaths and destruction that occurred Sept. 9.
In a press conference held in the laboratory that analyzed the ruptured pipeline, National Transportation Safety Board Chairwoman Deborah Hersman challenged PG&E’s theory that the pipeline’s flaws were some other company’s fault. PG&E admits to laying the faulty pipe 55 years ago, but has blamed the flaws on the factory pipeline manufacturer.
This distinction is crucial, because if it is determined that PG&E indeed manufactured the shoddy pipe, or had a substandard shop make it for them, the company may be legally more culpable for the disaster.
Though Hersman stopped short of saying that the pipeline was made by PG&E or by a local yard, she pointed to “a number of things that are not necessarily consistent with factory pipe.”
Specifically, she mentioned the quality of the pipeline materials, the orientation of the materials, and the strangely inadequate weld — none of which have been found elsewhere on factory-made pipe, she said.
The ruptured section of pipeline consisted of several small sections of pipes called “pups,” all pieced together with shoddy welds. But though those welds were problematic, the rupture instead occurred along a longitudinal seam that had not been welded from the inside.
Hersman slid her fingernail into the edge of one of these unwelded seams to demonstrate how precarious it was. She said PG&E has never been able to provide documentation about where the pups came from.
“We talk about them as mongrels because we don’t know what their pedigree is,” she said.
But PG&E spokesperson Brian Swanson said the company’s stance has not changed on the cause of the pipeline’s failure. He pointed to a document the company had filed with investigators that blamed the flawed seam on a manufacturer.
San Bruno survivor Tammy Zapata said she was eager to hear the results of the hearing, though she has already concluded on her own who is responsible for the disaster.
“I’m sick of PG&E saying it wasn’t their fault because they didn’t make the pipe, and it was the pipe manufacturer’s fault. If you’d looked at it once in the 60 years it was in the ground, you’d have known there was a flaw in it,” she said.
Facts of the blast
38 Homes demolished by pipeline explosion and subsequent inferno
8 People killed by blast
28 Feet of pipeline ejected from the earth during blast
100 Feet away from rupture site, the 28 feet of pipe landed
6 Small pieces of pipe, or “pups,” that made up the problematic section of pipe
0 Dollars PG&E has been fined by regulators so far
14,000 Pages of investigation material made public by NTSB
Sources: PG&E, NTSB, CPUC