Authorities say they’ve found the remains of two more people killed by the Thursday gas explosion in suburban San Francisco, raising the death toll to six. The blast destroyed 38 homes. The cause of the disaster is still under investigation, but the natural gas provider, Pacific Gas & Electric, has been dealing with pipeline accidents long before the explosion in San Bruno. Of the 87 major accidents on the state’s gas pipelines in the last decade, 43 involved pipelines belonging to the Pacific Gas & Electric. But it doesn’t necessarily mean this week’s explosion was entirely the company’s fault. Many accidents of this type can be caused by other people digging into the lines during construction. "Someone's doing construction on a site, they may or may not have called PG&E, they're working with a backhoe, they snag the pipeline, and then all it takes is a little ignition source," said one risk-management expert. Meanwhile, the company told regulators Friday that it was carrying $1 billion in insurance, but that it might not be enough to cover the damages of the fire.