WHILE LOADING THREE NEW CONVEYOR ONTO A SEMI TRAILER THE 3RD CONVEYOR SWAYED AND BUMPED THE TWO LOADED CONVEYOR 50' CAUSING THEM BOTH TO SLIDE OFF THE SEMITRAILER. EE, OTHER, AND ANOTHER WERE STANDING ON THE CATWALKS OF THE FIRST TWO CONVEYOR THAT WERE LOADED. AS THE CONVEYORS FELL THE EE FELL WITH THEM, STRIKING EE AND OTHER IN THE CHEST AREA AND BRUSING ANOTHER ARM.