Ken Miles died in a tragic single-vehicle accident on August 17, 1966, while testing the Ford J-car prototype at Riverside International Raceway in California. His car suddenly flipped at over 200 miles per hour, rolled multiple times, and burst into flames. Miles was ejected from the vehicle during the crash and died instantly from the impact
. The exact cause of the crash remains inconclusive. Ford conducted an extensive investigation, treating it like a flight crash, but due to the severe destruction of the car by impact and fire, no definitive mechanical failure was confirmed. Speculation includes possible mechanical failure or aerodynamic issues related to the car's design, but driver error was ruled out
. After the accident, Ford modified the car's aerodynamics and safety features, renaming it the Ford Mk IV, which went on to win races including the 1967 24 Hours of Le Mans
. There have been some conspiracy theories suggesting Ken Miles survived and lived in obscurity, but these have been strongly denied by those close to him and are not supported by credible evidence
