EE WAS BOLTING UP PIECE OF DRAW ROCK. STEEL GOT STOPPED UP & HE HIT IT WITH BOLT WRENCH. PIECE OF ROCK BROKE OFF & FELL AGAINST CANOPY & HE TURNED TO AVOID IT. IT HIT HIM IN BACK OF HEAD & NEC K. HE WAS TAKEN TO HOSPITAL AS PRECAUTIONARY, TREATED & RELEASED. WILL BE OFF COUPLE OF DAYS DUE TO STIFFNESS.