EE INSERTED AND 8' 3/4"" ROOF BOLT BETWEEN THE BOLTER CANOPY & THE ROOF TO BEND IT. AS HE PUSHED DOWN ON THE BOLT TO BEND IT THE BOLT SLIPPED AND HE STARTED TO FALL FORWARDS. HE FELL HE REACHED OUT TO CATCH HISSELF WITH HIS LEFT HAND WHICH RESULTED IN A FRACTURE TO HIS LEFT DISTAL RADIUS & ULNA. THIS OCCURRED IN THE FACE OF NO. 1 ENTRY ON THE EC-3 PANEL MMU 004-0. HAS MISSED NO WORK