SAN FRANCISCO — Minutes before eight people died in a fiery pipeline explosion, California utility crews raced to stop gas pressure surges they feared would cause a "major, major problem," call logs released by the federal government show.
Operators knew as long as half an hour before the Sept. 9 blast in a San Francisco suburb that a botched repair job in a nearby control station was letting natural gas flow unabated, but felt powerless to fix the problem remotely, according to Pacific Gas & Electric Co. records.
"Something opened that shouldn't have," one unnamed gas control operator told a colleague 20 minutes before the explosion. "They're scrambling in Milpitas right now trying to figure out what the hell opened and what's going on."
The National Transportation Safety Board is still investigating what caused the explosion, which employees called a "living nightmare" later that night.
Eight people died, dozens were injured and 55 homes were left uninhabitable after a giant, gas-fueled fireball swallowed portions of a neighborhood in San Bruno.
News organizations have been sifting through more than 4,000 pages of documents released by the NTSB last week during hearings in Washington.
Quoting from some of the call logs, the San Francisco Chronicle on Tuesday first reported details of the chaotic scene that evening as workers tried to pinpoint what was causing the problem on its high-pressure transmission lines running through numerous bedroom communities.
"We're screwed, we're screwed," another operator whose name was unclear in the log told a co-worker in the Milpitas control station, which lost power after crews tried to repair equipment, the logs showed.
Federal investigators have said the power failure at the control station, a major intersection for gas transmission lines about 30 miles from the blast site, allowed a regulating valve on the line feeding San Bruno to open fully and for pressure to rise.
But at 6:40 p.m., nearly half an hour after the explosion, workers were still debating whether a plane had hit, a gas station had blown up or the tragedy had been caused by a pipeline accident.
PG&E spokesman Joe Molica said in a statement Tuesday that the utility has been working with regulators since the accident to improve the safety of its system.
"We are not, however, waiting for mandates from legislators or regulators: PG&E already is making pipeline safety changes," he said. "We have launched a number of initiatives to reevaluate, restructure and strengthen our gas system operations and the management of our natural gas system. We have brought in independent experts to help us with our review of some of our gas control practices, including alarm management systems."
The section of pipe that ruptured was installed in 1956. An NTSB examination after the accident revealed it had a seam and inferior welds, although PG&E records had inaccurately identified the pipe as being seamless, which is considered safer.
Quoting from another document, The San Jose Mercury News reported Tuesday that PG&E decided 20 years ago against digging up the segment that later ruptured because the utility insisted its welds did not pose a risk to the public. Utility crews replaced five miles of aging gas pipes nearby but stopped just short of the spot that ruptured and exploded last year.
In January, however, federal investigators said they found dozens of defects and cracks in the welds holding together segments of the pipe.