Federal investigators issued a host of urgent safety recommendations Monday, pressing for major changes at the California utility responsible for the gas pipeline that exploded in a San Francisco suburb last year, killing eight people.
Six of the seven recommendations released by the National Transportation Safety Board were classified as urgent.
The board has been investigating what caused the Sept. 9 explosion that destroyed dozens of homes in San Bruno. Officials have not determined an exact cause but suspect the pipeline may have ruptured under high gas pressure.
One of the urgent recommendations asks Pacific Gas & Electric to identify all gas transmission lines that haven't yet undergone testing for safe operating pressures. The NTSB also urged California regulators to make sure the utility follows through on the testing.
The NTSB's recommendations follows a disclosure by federal accident investigators last month that the ruptured segment of the gas pipeline had a weld along its spine known as a seam weld. PG&E previously had submitted documents to state regulators showing it was unaware that the pipeline had the type of welds that investigators are now examining in their search for a cause for the explosion.
"While it may seem like a small paperwork error, if companies are basing operating pressures on inadequate or erroneous information contained in their records, safety may be compromised," said NTSB Chairman Deborah Hersman, who has testified before Congress on the need for pipeline reforms. "This safety-critical issue needs to be examined carefully."
Federal investigators also plan to hold a hearing in Washington in March about the explosion.
