EE WAS DOING ROUTINE MAINTENANCE AND MONITORING LINE 8 CASE PACKER. HE WAS STANDING ON PALLETS AND STARTED TO STEP OFF OF THE PALLETS UNTO A STEEL WALK PLATFORM AND SLIPPED AND FELL AGAINST AN OTHER STACK OF PALLETS. HE SUFFERED A NON-DISPLACED RIB FRACTURE TO THE 10TH RIB. ONT HE LEFT SIDE.