WHILE LOADING FRONT TRAILER, THERE WAS A SPILL; DRIVER TOLD BULK LOADER HE WOULD CLEAN IT UP WHILE BULK LOADER FILLED THE PUP; LOADER DID NOTHEAR THE DRIVER. DRIVER PULLED AHEAD AND THE LOADER, WHO WAS IN THE SAFETY CAGE, FELL WHEN THE TRAILER PULLED AHEAD; HE LANDED ON FENDER, BREAKING & DISLOCATING HIS LEFT SHOULDER, THEN FELL TO THE CONCRETE FLOOR BUMPING HIS HEAD.