Pacific Gas & Electric, aiming to show its determination to overcome a history of safety problems, announced Wednesday that it planned to put 10,000 miles of its power lines underground to prevent the kind of wildfires that led the utility to bankruptcy court.The project, which would involve about 10 percent of the lines currently above ground, could cost tens of billions of dollars to carry out. The announcement prompted questions from longtime critics of the utility about how much of the cost would be borne by ratepayers rather than shareholders.The company, California’s largest electricity provider, said the work would aim …
