A natural gas pipeline owned by Pacific Gas & Electric Co. burst Sept. 9, sparking a massive fireball that ripped through a San Bruno neighborhood. The explosion killed eight people and destroyed 37 homes.
The National Transportation Safety Board said it found weld issues along the San Bruno pipeline that may have led to the rupture. The NTSB said PG&E was called on to examine operating pressures to determine whether its gas transmission lines were safe to use.
Pipeline operators in the United States are also called on to consider the circumstances of the San Bruno disaster and take corrective measures to avoid another accident.
NTSB Chairwoman Deborah Hersman said safety was a critical and urgent issue for pipeline operators. A fact-finding hearing is scheduled for March to review the pipeline infrastructure in the United States.
"This accident has exposed issues that merit further attention and have implications for the pipeline infrastructure throughout the country," she said in a statement.
More than 50 residents in a San Bruno neighborhood filed a lawsuit against PG&E for not taking "corrective and life-saving action" in response to complaints of alleged signs of a gas leak before the Sept. 9 explosion.