WASHINGTON (Reuters) - Investigators on Tuesday blamed a utility's lax approach to pipeline safety and weak government oversight for a California natural gas explosion that destroyed a neighborhood and killed eight people nearly a year ago.
The National Transportation Safety Board (NTSB) said in a scathing report on the blast in San Bruno just south of San Francisco that the Pacific Gas & Electric Co for years exploited regulatory weaknesses.
"We also identified regulators that placed a blind trust in the companies that they were charged with overseeing to the detriment of public safety," NTSB Chairman Deborah Hersman said.
The half-century-old gas transmission line ruptured on September 9, 2010, ejecting a 28-foot section of pipe and igniting a ferocious fire that destroyed 38 homes and damaged 70 others. Eight people were killed and dozens of others were hurt.
The safety board found that the piping installed four-feet underground in 1956 did not meet certain specifications and the welds were poorly constructed.
Poor quality control and follow-up, the board said, resulted in the defective piping going undetected for decades. The blast, investigators said, was "clearly preventable."
Regulatory exemptions of certain regulations by the California Public Utility Commission and the U.S. Transportation Department contributed to the explosion, the safety board said.
The NTSB has issued a number of urgent safety recommendations to regulators and the pipeline industry to address the deficiencies it identified during its investigation.
PG&E officials could not immediately be reached for comment.
The California Public Utility Commission said it would work to ensure that PG&E correct any deficiencies. Additionally, the agency said it had ordered utilities to test or replace certain pipes and would evaluate NTSB recommendations for additional natural gas pipeline safety.
Transportation Secretary Ray LaHood ordered pipeline operators earlier this year to review their systems to identify potential problems for repair or replacement.
LaHood also asked Congress for legislation to give federal regulators more oversight and authority over "unsafe operators" and said he would work with industry, regulators and lawmakers to improve pipeline safety.
(Reporting by John Crawley; editing by Gunna Dickson)