On the afternoon of October 12, 1940 Mix was driving his 1937 Cord 812 Phaeton near Florence, Arizona (between Tucson and Phoenix) on a two-lane road when he came upon construction barriers at a bridge previously washed away by a flash flood. A workcrew watched as he was unable to brake in time and his car slid into a gully. A large, polished aluminium suitcase he had put on the seat behind him flew forward and struck Mix in the back of the head, shattering his skull and breaking his neck. The 60 year old actor was killed almost instantly. Accounts vary as to whether Mix was speeding before the accident, along with the role alcohol consumption may have played.