Pedestrian walking their dog was struck and killed by a commuter train near Sorrento Valley Road in San Diego, California

A man believed to have been out walking his dog was stuck and killed by a commuter train in Sorrento Valley early Thursday, authorities said.The crash happened about 6:30 a.m. near Sorrento Valley Road north of the transit center and involved a southbound Coaster train, a sheriff's official said.