EE WAS INSTALLING DECK GRATING AND BOLTING HANDRAIL. EE WAS WEARING HIS FALL PROTECTION EQUIPMENT BUT HAD TAKEN IT UPON HIMSELF TO DISCONNECT WHILE INSTALLING BOLTS. GRATING WAS NOT YET SECURE D AND SLID OUT FROM UNDER HIM CAUSING HIM TO FALL TO NEXT LEVEL. FALL BROKE BOTH WRIST AND CAUSED SMALL LACERATION TO RT CALF. NO OTHER INJURIES.