PERFORMING MAINTENANCE ON SAND COOLER INJ EE & COWORKER DESCENDED THE LADDER. INJ EE DECENDED THE LADDER. INJ EE MOUNTED THE LADDER THE WELD BROKE AND INJ EE FELL 16 FT ONTO HIS UPPER BACK. EE WAS TAKEN TO THE HOSPITAL FOR A EXAMINATION. EE ATTENDED SEVERAL FOLLOW UP VISITS.EE WAS REFERED TO A BACK SPECIALIST. PHYSICAL THERAPY WAS PRECRIBED.