One Dead After Sierra Highway Crash In Newhall One person was pronounced dead after a Sierra Highway crash in Newhall Wednesday night. Just before 8 p.m., Wednesday, reports were received of a traffic collision on Sierra Highway south of Needham Ranch Parkway, according to Supervisor Imy McBride With the Los Angeles County Fire Department. “It was a traffic collision that was reported on Sierra Highway near Clampitt Road,” McBride said. “There was one (dead on arrival).” The identity of the deceased was not available to KHTS as of Wednesday night, pending notification of next of kin. Sierra Highway was closed in both directions for an unknown duration due to the incident, according to officials on scene.