SAN BRUNO, Calif. —The section of gas pipeline that ruptured and exploded in a suburban San Francisco neighborhood, killing four and injuring nearly 60 others, was ranked as high risk because it ran through a highly populated area, state and federal authorities said Saturday.
One of the victims killed in the inferno Thursday worked for the commission reviewing Pacific Gas & Electric's investment plans to upgrade its natural gas lines, including another risky section of the same pipeline within miles of her home, a colleague confirmed.
Longtime California Public Utilities Commission analyst Jacqueline Greig and her 13-year-old daughter Janessa died in the massive blast, which left a crater near their house and laid waste to dozens of 1960s-era homes in the hills overlooking San Francisco Bay.
Jessica Morales, 20, was also killed in the explosion and fire. One other victim found earlier has yet to be identified, and authorities were trying to identify remains found Saturday morning. Two people were still missing after the blast.
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Greig spent part of the summer evaluating PG&E's expansion plans and proposals to replace out-of-date pipes, as part of the utility's overall bid to raise consumers' rates, co-worker Pearlie Sabino said.
Sabino and Greig were members of a small commission team that advocates for consumer protections pertaining to natural gas.
Among the paperwork PG&E submitted for hearings with regulators was a document ranking a section of the same gas line about two and half miles from the blast as within "the top 100 highest risk line sections" in the utility's entire service territory, documents show.
The federal Pipeline and Hazardous Materials Safety Administration classified the 30-inch diameter line, which ran for about a mile and a half in Greig's neighborhood, as a "high concentration area" requiring more stringent inspections, agency spokeswoman Julia Valentine said.
The state commission gave that section of pipe the same classification and had conducted audits on that stretch, spokeswoman Terrie Prosper said. PG&E also had conducted leak surveys, evaluations, and patrols on the gas line, she said.
Some residents were allowed back into a limited area to retrieve belongings, but San Bruno Mayor Jim Ruane said he doubted any would be able to return permanently Saturday.
"We want to make sure that the gas lines are safe," he said.
A group of local, state and federal officials toured the damaged area and described a ghost-town full of remnants of cars melted in driveways and pieces of houses, some left with just the chimney standing.
Officials were still trying to determine what led up to the blast. They took measurements of the blown out section of the steel gas pipe, and may send the sections to Washington, D.C., where examination under a microscope could help pinpoint what caused it to fracture, said Christopher Hart, vice chairman of the National Transportation Safety Board, who was at the scene.