SAN BRUNO, Calif. — Residents returned Sunday to the ruined hillsides of their suburban San Francisco neighborhood, three days after a natural-gas pipeline exploded into a deadly fireball.
A nearby risky segment of the gas line was due to be replaced, the utility responsible said, because it ran through a heavily urbanized area and the likelihood of failure was “unacceptably high.” That 30-inch diameter pipe a few miles north was installed in 1948 and was slated to be swapped for new, smaller pipe.
California regulators ordered the utility, Pacific Gas and Electric, to survey all its natural-gas lines in the state.
Investigators still don’t know what caused the blast Thursday night. Even as dozens of people returned to their scorched homes — accompanied by gas workers to help restore pilot lights and make sure it is safe to turn power back on — officials tried to confirm just how many people died.
The remains of at least four people have been found, and authorities have said four are missing and at least 60 injured, some critically. Two people reported missing after blast were found Sunday, said city spokeswoman Robyn Thaw.
San Mateo County Coroner Robert Foucrault said they are still trying to confirm whether some of the remains they found are human and identify victims.
Streets were crowded Sunday with PG&E cars and trucks, and representatives were handing out gift certificates for grocery stores. Nearly 50 homes were destroyed and seven severely damaged in the blast, while dozens of other homes suffered less severe damage in the fire that sped across 15 acres.
Pat and Roger Haro and their dog, Rosie, have been living in a hotel room since Thursday, after fleeing their home with the clothes they were wearing, dog food, water and an iPad.
When they returned, their home was marked with a green tag — indicating less damage than others with yellow or red tags — and their electricity was still off.
“Once I saw the house was still there, then I felt a whole lot better,” Pat Haro said.
Meanwhile, local and federal officials are probing the cause of the explosion that blew a segment of pipe 28 feet long onto the street about 100 feet away, creating a crater 167 feet long and 26 feet wide.
PG&E submitted paperwork to regulators for ongoing gas-rate proceedings that said a section of the same gas line about 2 1/2 miles away was within “the top 100 highest risk line sections” in the utility’s service territory, the documents show.
PG&E spokesman Andrew Souvall said the ruptured section, which was installed in 1956, was last checked for leaks in March. The company said later Sunday no leaks were found.
On Saturday, new information surfaced about a 2008 sewer project that could have weakened the gas line, San Jose Mercury News reported.
Records show that two years ago, the San Bruno City Council hired a construction company to replace underground sewer lines in the same area as the location of the pipeline that exploded. But PG&E vice president Geisha Williams said that the utility inspected the gas line before and after the sewer work and found no problems.
