When one thinks of the worst industrial accidents in United States history, the Triangle Shirtwaist Factory fire of 1911 springs to mind. One-hundred-forty-six workers, most of them poor, Jewish and Italian immigrant women and girls, died when a fire engulfed three floors of the factory's building. Horrifyingly, the stairwell doors and exits were locked, standard operating procedure for supervisors hoping to maximize productivity, curb theft and keep out union organizers. The sole fire escape collapsed as the workers tried to flee and the firefighters' rescue ladders couldn't extend high enough, leaving dozens of the women to jump to their deaths.