THE EMPLOYEE WAS PREPARING TO VACUUM WATER FROM A SUMP. HE SLIPPED ON WET CONCRETE AND FELL ONTO A 1 FT HIGH CONCRETE FOOTING ON HIS UPPER BACK. HE BRUISED HIS BACK AND WAS RELEASED TO FULL DU TY THAT DAY. HOWEVER HE DID NOT REPORT TO WORK ON 9/8/03, COMPLAINING OF BACK PAIN. HE REPORTEDLY HAS A HISTORY OF BACK PROBLEMS AND HIS CHIROPRACTOR TOLD HIM HE SHOULD NOT PERFORM LABOR. HE