by: Laura Parker
(Sept. 10, 2010)
-- Damaged pieces of 30-inch steel pipe pulled from the ashes
may tell the tale of what happened in Crestmoor Canyon on
Thursday night, when gas from a ruptured transmission pipeline
fed a fire so intense it devoured 15 acres of houses in the
San Francisco suburb of San Bruno, Calif., and killed four
is that the accident, coming on the heels of the BP disaster
in the Gulf of Mexico, will once again cast a spotlight on
the effectiveness of state and federal safety regulations
governing the energy industry. Regulations passed by Congress
in 2002 require safety inspections of gas pipelines in densely
populated areas by 2012. A new agency, the Pipeline and Hazardous
Materials Safety Administration, was set up in 2004 to "protect
the American public and the environment by ensuring the safe
and secure movement of hazardous materials," according
to the agency's mission statement. There are more than 2 million
miles of natural-gas pipeline in the United States.
going to be a major event," said Jim Hall, who chaired
National Transportation Safety Board during the Clinton administration
and made pipeline safety his cause. "All of these underground
pipelines are potential bombs."
The overhaul of pipeline safety laws followed a spate of fatal
pipeline accidents in the late 1980s and 1990s. The NTSB pushed
for new inspection regulations and replacement of aging pipelines,
some of which are more than 50 years old.
Hall, who has
often given speeches on pipeline safety, told AOL News in
an interview that the accident in San Bruno will be the first
major test of the new regulations.
aren't enough facts yet to draw any conclusions about this
event," he said. "But it certainly presents us with
an opportunity to closely examine how well the new legislation
president of the Interstate Natural Gas Association of America,
an industry trade group based in Washington, said the programs
put in place after 2002 have reduced risk. "Compared
to other modes of transportation, pipelines are among the
safest," he said.
investigators converged in San Bruno to begin a forensic examination.
A four-member team from the NTSB, which will head the probe,
arrived at the scene Friday afternoon to begin collecting
physical evidence and records from the pipeline's owner, Pacific
Gas and Electric Co.
investigators will be joined by state and local officials,
including a team from the California Public Utilities Commission,
which has state jurisdiction over the pipeline, though federal
regulations also apply.
of the pipeline explosion may prove easier to solve than the
"why." The usual culprits in pipeline breaks are
construction crews or other workers who run into the pipeline
while excavating for some other purpose. In some cases, the
damage is not immediately apparent. If a pipeline is merely
scraped, as opposed to punctured outright, years could pass
before metal fatigue sets in and the pipe finally gives way.
That is what
happened in Edison, N.J., in 1994 when a 36-inch gas-transmission
line ruptured, causing an explosion that burned eight buildings
in an apartment complex and forced the evacuation of 1,500
residents. NTSB metallurgists found a gouge in the pipe that
weakened it over time. Eventually, a crack grew in the gouge
until it reached "critical size," according to the
NTSB report of the accident.
But from there questions can be many, and complicated. Was
the pipe properly installed? What kind of soil was it buried
in? Had it been dislodged from its bed? When was the neighborhood
developed after the pipeline was installed? Had the pipeline
been repaired? Were the repairs done properly? What kind of
monitoring system tracked the flow of gas? Was a warning system
The San Bruno
accident was so devastating because it involved a large transmission
line, which exploded in an area where the pipeline was buried
just 3 feet deep. Transmission pipelines deliver natural gas
to utilities, large industrial customers and municipalities
for further distribution to homes and businesses, according
to the pipeline administration's website.
will want to know when the pipeline was last inspected. In
California, state inspectors carry out the checks under an
agreement with the federal Transportation Department.
It is unclear
the travel route of the pipeline involved in Thursday's explosion,
or where the gas was to be delivered. Nicole Liebelt, a PG&E
spokeswoman, told AOL News that that information would not
be immediately available.
In its investigation, the NTSB investigators will also examine
a previous explosion involving a PG&E gas pipeline in
2008 in Rancho Cordova, Calif., that killed a homeowner, injured
five people and damaged several homes. That explosion was
caused by gas leaking from an unmarked and improperly sized
pipe in the house that had allowed gas to leak from a mechanical
coupling installed two years earlier, the safety board concluded.
two incidents are vastly different, they may have one thing
in common: a customer complaint called into PG&E beforehand.
The way the company responded will surely draw investigators'
In the 2008
incident, the company dispatched a technician five minutes
after the homeowner called in to report he'd smelled gas.
But the technician could not resolve the problem. After a
series of delays, a leak inspector finally arrived two hours
and 47 minutes after PG&E received the initial report.
The safety board concluded that the long delay contributed
to the cause of the accident.
In San Bruno, residents said neighbors had reported to PG&E
that they smelled gas in the area. PG&E President Chris
Johns said the company has not confirmed that it received
any complaints. But he added that the company has no record
of its crews working in the area at the time of the explosion.
p.m., residents reported hearing a sound so deafening some
thought at first a plane had crashed. The fireball sent flames
soaring more than 60 feet into the air. In addition to the
four people who died, 24 others were injured, five of them
The fire was
so fierce firefighters were still trying to contain the blaze