San Bruno pipeline explosion
| Industry | Energy (Natural gas and electricity) |
|---|---|
| Headquarters | San Francisco , United States |
| Products | Natural gas transmission and distribution, Electricity transmission and distribution |
| Website | pge |
The San Bruno pipeline explosion took place at 6:11 pm PDT on September 9, 2010, in San Bruno, California. A steel natural gas pipeline with a diameter of 30 inches, owned by Pacific Gas & Electric (PG&E), ruptured and exploded in the Crestmoor residential area, located roughly 4 miles southwest of San Francisco International Airport. The explosion occurred near the intersection of Skyline Boulevard and San Bruno Avenue, causing significant destruction. Initially, the blast was mistaken for either an earthquake or an airplane accident. It took emergency personnel close to an hour to identify the cause as a natural gas pipeline rupture.
By September 29, 2010, the disaster had claimed eight lives and injured 58 individuals. The United States Geological Survey recorded the explosion and its shockwave as equivalent to a magnitude 1.1 earthquake. Witnesses described seeing a fireball rising over 1,000 feet into the sky immediately following the blast, which ignited a large-scale fire that ravaged the surrounding neighborhood.
Explosion and fire
At precisely 6:11 pm PDT on September 9, 2010, a powerful explosion struck the Crestmoor neighborhood of San Bruno near Skyline Boulevard and San Bruno Avenue. This event ignited a rapidly spreading fire that consumed multiple nearby residences. Firefighters evacuated adjacent areas amid strong winds that intensified the flames and complicated suppression efforts. The cause was traced to a broken gas pipeline, with gas flow being halted between 60 and 90 minutes after the blast according to San Bruno Fire Chief Dennis Haag. The incident resulted in the destruction of between 35 and 38 homes, with at least eight additional houses sustaining damage; three of these damaged structures were demolished in December. Around 200 firefighters responded to battle what was classified as an eight-alarm fire.
The explosion left behind an irregularly shaped crater measuring approximately 167 feet in length, 26 feet in width, and 40 feet deep along Glenview Drive. Most of the homes destroyed were situated eastward along Claremont Drive. The fire also damaged a water main, forcing firefighters to rely on water transported by trucks while residents extended hoses nearly 4,000 feet to reach operational hydrants. Assistance came from across the Bay Area through mutual aid agreements, including resources from the California Department of Forestry and Fire Protection, which deployed 25 engines as well as airtankers, air attack planes, and a helicopter.
By 10 pm that evening, containment of the fire had reached only about fifty percent and it continued burning until approximately 11:40 am the following day.
As of September 29, eight fatalities had been confirmed. Among those who died were Jessica Morales and Jacqueline Greig—an advocate for consumer rights regarding natural gas regulations employed by the California Public Utilities Commission—and Greig’s daughter Janessa. Other victims included Elizabeth Torres (81), Lavonne Bullis (82), Greg Bullis (50), and Will Bullis (17). Joseph Ruigomez survived despite being at ground zero but underwent nearly five months of treatment at Saint Francis Memorial Hospital Burn Center.
San Bruno
In response to the disaster, a Red Cross shelter was set up at San Bruno’s Veterans Memorial Recreation Center. The Blood Centers of the Pacific issued an urgent call for blood donations. Evacuated residents were temporarily housed at locations such as The Shops at Tanforan and Bayhill Shopping Centers. All elementary schools within the San Bruno Park Elementary School District as well as Parkside Junior High School were closed on September 10; however, Capuchino High School remained operational. By September 12, residents whose homes were undamaged were permitted to return.
Pacific Gas and Electric Company
The pipeline involved in the explosion was owned by the Pacific Gas and Electric Company (PG&E). On September 10, 2010, Christopher Johns, PG&E's president, indicated that the company was unable to access the explosion site for inspection. The affected pipeline was a steel transmission line. After the incident, PG&E's stock value declined by eight percent, resulting in a $1.57 billion decrease in market capitalization.
Following investigations suggesting possible faulty pipeline installation, PG&E lowered operating pressures by 20 percent. The California Public Utilities Commission (CPUC) mandated PG&E to review maximum operating pressures on roughly 1,800 miles of pipeline. By the March 2011 deadline, PG&E had not provided documentation confirming pressure testing for certain pipelines.
In August 2011, PG&E unveiled a comprehensive multi-year initiative aimed at modernizing and improving gas transmission safety. This plan included automating over 200 valves, conducting strength tests on a significant portion of pipe, replacing sections of pipeline, and enhancing approximately for in-line inspection capabilities. The initial phase focused on urban areas and outdated pipelines, with $769 million proposed to be funded through a three-year rate increase starting January 2012.
On November 6, 2011, an explosion occurred during strength testing near Woodside, California, triggering a mudslide but causing no injuries.
California state government
Lieutenant Governor Abel Maldonado declared a state of emergency and issued an executive order to support those affected. State authorities required PG&E to inspect all natural gas pipelines under its control within California. Governor Arnold Schwarzenegger visited the site shortly after returning from an Asia trade mission.
Federal government
U.S. Representative Jackie Speier described the incident as "a very serious crisis" and urged the Federal Emergency Management Agency (FEMA) to designate the area as a national disaster zone.
Use of technology
Local technology firms including Cisco Systems and Google deployed emergency response teams to assist with communications and advanced mapping at the request of first responders. These efforts were coordinated by nonprofit organization InSTEDD, supported by Carnegie Mellon University's Disaster Management Initiative, with volunteers aiding Geographic Information Systems (GIS) operations under the direction of the Planning Section Chief.
Investigation
San Bruno Police declared the vicinity a crime scene to investigate potential criminal activity. The National Transportation Safety Board (NTSB) initiated an inquiry into the explosion's origin. Prior to the blast, residents reported detecting natural gas odors. A PG&E source identified a rupture in natural gas line number 132 as the cause; pressure at that moment was about 386 psi, exceeding PG&E's maximum operating pressure by 11 psi but remaining below its maximum allowable limit of 400 psi. The pipeline was a large-diameter, 30-inch steel pipe.
NTSB vice chairman Christopher A. Hart stated that the damaged pipe section measured 28 feet in length and was propelled approximately 100 feet by the explosion. The blast created a crater initially reported as measuring 167 by 26 feet but later corrected to 72 by 26 feet. The pipe was composed of multiple welded segments with longitudinal seams; while these welds do not necessarily indicate repairs, they represent potential weak points compared to newer seamless pipes.
In January 2011, federal investigators discovered numerous defective welds characterized by inconsistent pipe wall thickness and incomplete weld penetration. These flaws were exacerbated when PG&E increased pipeline pressure to meet growing demand. Installed in 1956, this pipeline predated contemporary testing techniques such as X-ray inspections.
The NTSB conducted a three-day public hearing in March 2011 involving representatives from Pacific Gas & Electric, the California Public Utilities Commission (CPUC), Pipeline and Hazardous Materials Safety Administration (PHMSA), City of San Bruno officials, and International Brotherhood of Electrical Workers Local 1245.
Call records revealed that an uninterruptible power supply (UPS) replacement took place at PG&E’s Milpitas gas terminal hours before the explosion; technicians experienced electrical irregularities during this replacement but successfully restarted systems.
PG&E had replaced portions of Line 132 near the San Andreas Fault to mitigate earthquake risk but had not extended these replacements to the segment that failed.
On January 13, 2012, a state audit in California reported that PG&E had improperly redirected over $100 million from safety budgets toward executive salaries and bonuses.
Private party
More than 100 plaintiffs, represented by upwards of 20 law firms, initiated over 70 lawsuits against Pacific Gas and Electric (PG&E) and its parent corporation in various California Superior Courts, predominantly within San Mateo County. These cases were merged into Judicial Council Coordinated Proceeding (JCCP) No. 4648, referred to as the PG&E "San Bruno Fire" Cases. On June 3, 2011, plaintiffs filed a unified Master Complaint.
PG&E’s response came on July 5, 2011, asserting standard defenses including the use of state-of-the-art technology and claims of comparative negligence. In July 2012, depositions were presented by plaintiffs alleging that PG&E leadership disregarded employee warnings about inaccuracies in Geographic Information System (GIS) data critical for pipeline inspections.
By September 2013, PG&E had reached settlements with 347 claimants, supplementing previous agreements involving 152 claimants, culminating in $565 million for a total of 499 victims. Although two lawsuits remained pending at that time, they were subsequently reported as encompassed within the overall settlement amount. According to PG&E’s 2015 annual report, payments to third parties amounted to $558 million along with $92 million in legal expenses, partially offset by $515 million recovered from insurance.
State of California
In October 2012, public hearings regarding the San Bruno pipeline explosion were put on hold while state regulators and PG&E negotiated penalty terms. Rene Morales, mother of Jessica Morales—one of the eight victims—called on Governor Jerry Brown to appoint a new president to the California Public Utilities Commission (CPUC). Former Senator George J. Mitchell was designated to oversee settlement discussions. Subsequently, in December 2012, the CPUC determined that electricity customers would bear 55% of the $229 million in long-term costs associated with PG&E’s pipeline inspection and safety enhancements.
On September 16, 2014, it was disclosed by the San Francisco Chronicle that Carol Brown, chief of staff to the CPUC president, had engaged in communications with PG&E executives aimed at influencing litigation outcomes through the selection of favorable judges. By October 2014, this judge-selection controversy was under federal investigation. In 2018, PG&E was penalized $92.5 million by the CPUC for improper contacts with commissioners and their staff.
On April 9, 2015, the Public Utilities Commission levied a historic $1.6 billion fine against PG&E related to the San Bruno disaster.
Federal
On April 1, 2014, a federal grand jury in the United States District Court for the Northern District of California indicted PG&E on multiple counts of violating the Natural Gas Pipeline Safety Act of 1968, specifically concerning its record-keeping and pipeline integrity management practices. A subsequent indictment on July 29, 2014, charged the company with obstruction of justice for providing misleading information to the National Transportation Safety Board about its pipeline testing procedures, raising the total charges to 28 counts. Possible penalties included fines up to $1.3 billion tied to profits from wrongdoing plus an additional $2.5 billion for breaches of state regulations.
On January 21, 2017, PG&E was fined $3 million and ordered to complete 10,000 hours of community service for violations related to the Natural Gas Pipeline Safety Act and obstruction of justice. The company was also mandated to establish a compliance and ethics oversight program and allocate up to $3 million toward publicizing its criminal convictions following a federal jury’s guilty verdict in August 2016 on six out of twelve charges.
In 2017, PG&E resolved a shareholder class action suit accusing the company of severe mismanagement by agreeing that its insurer would pay $90 million, alongside allocating $32 million toward enhancements in safety and corporate governance.
Media coverage
Brigham McCown, former head of the Pipeline and Hazardous Materials Safety Administration, advocated for establishing a national commission to tackle concerns related to high-pressure fuel pipelines situated within residential zones. He proposed implementing buffer zones around such pipelines as a preventive measure against potential disasters.
A memorial dedicated to the victims was unveiled on September 9, 2012, at San Bruno City Park.
See also
External links
- San Bruno explosion map – Interactive visualization provided by the Los Angeles Times.
- "Resources for San Bruno Residents" (KGO-TV)
- Aerial photograph of the aftermath – Captured November 9, 2010
- Before and after comparison photos
- Photo gallery and related news links
- Commercial pilots recognized it was not an aircraft crash – Video
- Surveillance footage from a gas station located approximately a quarter mile away – Video
- Surveillance video inside a nearby grocery store – Video
- National Pipeline Mapping System – Locations of gas transport pipelines
- PG&E and CPUC email correspondence – Collection of 65,000 messages
- NTSB Report on San Bruno PG&E gas pipeline failure
- San Bruno, California
- Fires in California
- Explosions in California
- 2010 disasters in the United States
- Gas explosions in the United States
- Pipeline accidents in the United States
- History of San Mateo County, California
- Pacific Gas and Electric Company
- 2010 industrial disasters
- Urban fires in the United States
- Explosions in 2010
- 2010 crimes in California
- Energy in the San Francisco Bay Area
- September 2010 in the United States