THE EMPLOYEE WAS CLEANING THE TRAYS OF THE TRUNNION ROLLERS ON THE 3RD PIER AT THE #3 KILN. AS HE WAS COMING DOWN OFF THE PEIR AND ONTO THE CATWALK, THE EMPLOYEE STEPPED ONTO A BLOCK THAT WAS ON THE WALKWAY. THERE WAS A CONTRACTOR PRESENT AT THE SITE. EMPLOYEE WAS BEING CARELESS, BUT CATWALK NEEDED TO BE CLEAR OF DEBRIS.