Gas line explosion in San Francisco sets buildings on fire

San Francisco firefighters battle a fire on Geary Boulevard in San Francisco. Photo / AP

A gas explosion in a San Francisco neighbourhood shot flames high into the air today and was burning four buildings as utility crews scrambled to shut off the flow of gas.

Construction workers cut a natural gas line, San Francisco Fire Chief Joanne Hayes-White said. Authorities initially said five of them were missing, but the entire construction crew was found safe, and no other injuries were reported.

Hayes-White said several buildings in the area were evacuated, including a medical clinic and several apartment buildings.

"It's pretty dramatic, but we have pretty good handle on it," she said.

Firefighters worked to keep the fire from spreading while Pacific Gas & Electric crews have been trying for more than an hour to shut off the natural gas line.

"It's complicated," Hayes-White said of stopping the flow of gas through the damaged pipe.

PG&E, which is under heightened scrutiny over its gas pipelines, didn't immediately return a phone call seeking comment.

A US judge fined the nation's largest utility US$3 million for a conviction on six felony charges of failing to properly maintain a natural gas pipeline that exploded under a neighbourhood south of San Francisco in 2010.

The explosion killed eight people and wiped out a neighbourhood in suburban San Bruno. California regulators also fined PG&E US$1.6 billion, and the utility remains under a federal judge's watch in that case.

Today's fire began, apparently by crews working on fibre-optic wires, Hayes-White said.

"I anticipate the gas line was breached by the workers," the fire chief said.

Joseph Feusi lives four blocks from the fire and said he was awoken by what sounded like a jet engine.

Feusi works nights and sleeps in the afternoon, saying he could see the towering flames from his home.

"I think the eight guys are really lucky they didn't get blown to bits," he said.

- AP