Gene Rychlak (RIP) once dropped ~1000lbs on his upper torso, although that was one of the early "the Shirt" lifts. Think the shirtless WR mighta been around 710-15 at the same time, by way of comparison to this Maddox lift. There were spotters around, they weren't slack, Gene just gave out so suddenly they couldn't react.
He seemed to recover well; that "RIP" I put up there was not from the accident. Cause of death @ 51yo was just normal to be expected heart stuff from someone who pursues HUGE, but I always wondered if that accident caused some undiagnosed heart or blood vessel damage from impact that killed him slowly rather than instantly.