BUENA PARK, Calif. (KABC) -- A female pedestrian was killed in a hit-and-run crash on the 91 Freeway in Buena Park early Tuesday morning.The crash occurred shortly before 5 a.m. on the Valley View Street off-ramp on the westbound side of the freeway.It was not known why the woman was on the freeway at the time of the collision.The California Highway Patrol did not have a description of the hit-and-run suspect or the suspect's car.The victim's identity was not immediately released.CHP officials said witnesses called 911 reporting that a woman was walking on the freeway.Responding officers say they arrived on scene and saw the woman had been struck by at least one vehicle.The Valley View Street off-ramp was shut down as investigators gathered evidence, hoping to track down the driver or drivers responsible.