EMPLOYEE SLIPPED ON A STEEL SHELL OF A CHUTE TO A STACKER RE-CLAIMER UNDER CONSTRUCTION ON 2-22-01. EMPLOYEE REPORTED MINOR INJURY TO SUPERVISOR OF A SLIGHT SPRAIN OF SIDE ABDOMINAL MUSCLES. ON 3-28-01 EMPLOYEE ARRIVED TO WORK COMPLAINING OF WORSENING PAIN. SENT TO DOCTOR ON 3-29-01.