Here's the story from the L.A. Times:
At least four people were killed and 52 injured in the gas pipeline explosion and fire that rocked a San Bruno neighborhood as investigators Friday tried to determine what caused the devastating blast that left a crater in the ground and homes smoldering.
Lt. Gov. Abel Maldonado, serving as acting governor while Gov. Arnold Schwarzenegger is in Asia, declared a state of emergency in the Crestmoor neighborhood and said the blaze was 75% contained after destroying 15 acres. "We don't know what caused [the rupture]," Maldonado said in a news conference near the scene. "We will find out soon."
A total of 52 people have been hospitalized, including three with third-degree burns. Four firefighters who suffered smoke inhalation were treated and released. Maldonado said a natural gas line ruptured about 6:24 p.m. Thursday, ripping a crater in the neighborhood and causing the blaze, which consumed 38 structures and damaged seven more. Some 67 pieces of firefighting apparatuses were brought in to fight the blaze, including four air tankers that proved the most important in attacking the ferocious blaze most of the night, when firefighters were unable to do much from the street. Twelve trained dogs were also at the scene Friday to help in the search for bodies. "The sun is shining over there, but there is still a dark cloud over the city of San Bruno," Mayor Jim Ruane said.
Pacific Gas & Electric officials said Friday they were investigating reports that customers complained of a natural gas odor before the deadly explosion. They also said the damaged section of the 30-inch steel gas pipeline has been isolated and the gas flow turned off, and crews planned to walk the neighborhood Friday to survey the damage and check the gas transmission system.
Company officials said they would cooperate fully with federal, state and local agencies to identify the cause of Thursday's explosion. They did not say, however, whether the pipeline caused the explosion. “That will be part of the ongoing investigation. [The National Transportation Safety Board] will be conducting a comprehensive investigation and we will be cooperating fully,” said Jeff Smith, a spokesman for the utility. PG&E officials in a statement said crews are working to make the area safe, assess damage and restore service where possible.