While rigging up a drill rig, derrick was in horizontal position suspended approx 1' via the gantry rigging. A gussett supporting a wire rope saddle failed allowing the line to slip off. The derrick fell the 1' onto crib blocks. EE was maneuvering the crib block at the time, intending to expose the derrick area in order to paint it. His hand was caught btwn the cribbing & derrick.