EMPLOYEE WAS WORKING AT THE CRUSHER TO REMOVE A PLUG OF ROCK. A GRATING HAS BEEN REMOVED IN ORDER TO ACCESS AN INSPECTION DOOR ON THE TOP OF THE CRUSHER. AFTER REPLACING THE INSPECTION DOOR, THE EMPLOYEE WAS STANDING ON THE DOOR AND ATTEMPTING TO REMOVE DIRT FROM AROUND THE HINGES. HE STEPPED BACKWARD AND RIGHT LEG WENT THROUGH A GAPBETWEEN THE DOOR AND GRATING. THIGH & BACK STRAI