CRUSHING CREW WAS CLEANING THE HAMMER MILL THAT HAD PLUGGED ITSELF WITH ROCK AFTER THE HAMMER MILL DISCHARGE MOTOR HAD QUITR WORKING. AFTER SOME CLEANING ANOTHER EE TOLD EVERY ONE TO STAND CLE AR SO THAT HE COULD START THE DIESEL DRIVE OF THE MILL & REPOSITION HAMMERS FOR FURTHER CLEANING. EE REACHED IN MILL TO GRAB A LARGER ROCK & DISCARD IT. HAMMER FELL PINCH FOREARM, TORN ARTERY