California Gov.-elect Jerry Brown speaks during a news conference at his campaign headquarters on Nov. 3, in Oakland, California. David Paul Morris/Getty Images hide caption

itoggle caption David Paul Morris/Getty Images

A piece of the ruptured pipeline from last month's fatal accident in San Bruno, Calif., displayed in a laboratory at the National Transportation Safety Board's training center in Ashburn, Va. A preliminary NTSB report says a power failure led to a brief change in pipeline pressure but does not say that the pressure change caused the blast that killed eight people and destroyed 37 homes. Luis Alvarez/AP hide caption

itoggle caption Luis Alvarez/AP

A worker with the Downtown Oakland Association sweeps the sidewalk near graffiti painted by protesters outside a drug store in Oakland on Friday. The federal government said it will investigate now that officer Johannes Mehserle was convicted Thursday of involuntary manslaughter, touching off angry protests that damaged stores and netted dozens of arrests. Eric Risberg/AP hide caption

itoggle caption Eric Risberg/AP