The Flame and the Arrow (1950)
Veteran stuntman Duke Green was seriously injured doing a stunt in The Flame and the Arrow. He was supposed to catch his foot in a snare on a forest pathway and be whipped upright off his feet. The rigging from the platform above him broke, and he plunged to the ground, breaking his neck. He eventually recovered to a degree and did some minor stuntwork in the years following, but the injury effectively ended his 25-year career as a stuntman.
https://www.imdb.com/title/tt0042464/trivia?item=tr2897235.