EE'S WERE ATTEMPTING TO MAKE ADJUSTMENT TO THE CONE. INJURED EE WAS NOT FOLLOWING ESTABLISHED RULES NOR USING COMPANY SUPPLIED SAFETY EQUIPMENT. DURING WORK EMPLOYEE SLIPPED ON DAMP STEEL & FELL LANDING ON BACK & HIP. THOUGHT HE HAD KNOCKED THE WIND OUT OF HIMSELF. DIDN'T REPORT ACCIDENT UNTIL DAYS LATER. DIAGNOSED WITH CONTUSIONS TO BACK, HIP, RIGHT SHOULDER.