OK so I'm reading Generation X (ten years too late of course but never mind that) and there's a reference to a movie that killed over half the cast and crew. Turns out (and you may know this already but I didn't) that stat is slightly exaggerated. At least 91 of the 220 cast and crew of The Conqueror contracted cancer subsequent to filming. The director, Dick Powell, and the stars, John Wayne, Susan Hayward, Pedro Armendáriz, and Agnes Moorehead, were included in the victims.
It seems that the Snow Canyon, Utah area where the movie was filmed had been acting as a natural reservoir for fallout from military nuclear tests at Yucca Flats, upwind. The nearby residents of the town of St George seem to have suffered also with very high cancer rates, although there is no mention on the city's website (apparently that area has a lovely climate and lots of scenic beauty, oh and some top notch cancer facilities). All I could find was this.
This was the last movie Howard Hughes ever made before he went nuts.