WALKED DOWN GABION BELT CATWALK TO UNSTOP GABION CHUTE. PICKED UP 8-LB. SLEDGE HAMMER WITH RIGHT HAND. ATTEMPTED TO STEP FORWARD AND DOWN TO METAL BOX LOCATED AT BOTTOM OF GABION CHUTE AND ONTO THE GABION BOX LEDGE WHICH IS APPROX. 12 INCHES IN WIDTH. STEPPED DOWN APPROX. 8-10 INCHES ONTO THE BOX LEDGE - LEFT FOOT CURLED AND TWISTED ANKLE.