EMPLOYEE WAS PULLING LOOSE OFF THE RIB FROM A WORK BACKET WHEN A LARGE ROCK BROKE FREE FROM RIB & FORCED BAR BACK CAUSING HIM TO LOOSE HIS BALANCE & FALL INTO THE TOP RAIL WITH HIS LEFT SHOULD ER/COLLAR BONE. INJURED WAS TRANSPORTED VIA AMBULANCE TO HOSPITAL. X-RAYS REVEALED NO BROKEN BONES AND EMPLOYEE WAS RELEASED TO COMPANY DOCTOR. COMPANY DOCTOR PLACED EMPLOYEE OFF WORK ON 11/1