The numerous safety violations that contributed to a deadly train crash in California last year have some federal officials asking whether the crash was an isolated incident or part of a more widespread problem, particularly with cell phone use by crew members. A National Transportation Safety Board panel held a second day of hearings Wednesday concerning the crash that killed 25 people and injured at least 130. The crash occurred when a Metrolink passenger train failed to heed a red traffic signal and ended up on the same shared track with a Union Pacific freight train, officials said.
