'The Conqueror' (1956) Howard Hughes' ill-fated Genghis Khan epic suffered from a host of problems, not the least of which was miscasting of John Wayne as the Mongol warlord. The dialog was terrible and made worse by Wayne's line-readings. A black panther tried to take a chunk out of female lead Susan Hayward and a flash flood nearly wiped out the entire crew. But it was the film's location that gave "The Conqueror" it's most infamous legacy. It was shot in Utah's Snow Canyon, which had been the destination of huge clouds of fallout from the U.S. Army's Yucca Flats nuclear weapons tests of the 1950s. Of the 220 crew members working on the film, 91 eventually developed cancer and 46 died -- including Wayne himself. Though the high levels of radiation were known to the crew, they weren't taken seriously until the cancer manifested itself. Hughes took on much of the guilt himself, and is reported to have screened the movie over and over again during his later years. RKO Radio Pictures Inc.