At One Madison, a high-rise under construction on 23rd Street in Manhattan, workers face dangers daily: live wires, electrical hazards, heavy machinery. Cold gusts of wind whip around them as they lay concrete and operate forklifts. Access to the upper floors of the 28-story building is a ride on a noisy construction elevator. City and federal officials visited the site recently to give a safety presentation, but they weren’t there to remind workers how to avoid falls or injuries. They were show