Overview: On June 6, 1971, Hughes Airwest Flight 706, a Douglas DC-9-31, enroute from Los Angeles, California, to Salt Lake City, Utah, collided in mid-air with a McDonnell Douglas F-4 Phantom II, of the U.S. Marine Corps, over the San Gabriel Mountains, near Duarte, California. The F-4 pilot and all 49 passengers and crew on board the civilian airliner died; the Radar Intercept Officer of the F-4 survived. Join the NTSB and military experts as they work together to uncover how a fighter jet could collide with a civilian airliner.