You've heard the one about the construction worker who lowers a barrel of bricks from three or four floors up via a pulley system but misjudges the weight. It pulls him up to the top, hitting him on the way up. He jams his fingers in the pulley, the barrel hits the ground and breaks open spilling the bricks. The barrel, now being lighter than he, rushes back up, hitting him a second time, he hits the ground, lets go of the rope and the barrel comes back down and hits him again.
They actually got it to work. Did it twice. Really funny to see what happened to the crash test dummy. Wasn't meant to be hit with 180lbs of bricks!