EMPLOYEE WAS REMOVING FORMS FROM #2 THICKNER PUMP SUMP. EE REMOVED THE PINS THAT WERE SECURING THE FORM HE WAS TIED OFF TO, THE FORM & EE FELL TO THE GROUND. CONTRIBUTING CAUSES; FAILURE TO RECOGNIZE HAZARDOUS SITUATION, NOT FOLLOWING SAFE METHODS, TAKING IMPROPER POSITION. EE HAD IMPACTED FRACTURE TO RIGHT RADIAL.