EE WAS LOWERING DRILL POT ON ROOF BOLTER WHEN HYDRAULIC HOSE CAUGHT A DRILL STEEL THAT WAS OVERHANGING IN TRAY CAUSING STEEL TO FLIP UP AND STRIKE HIM ON RIGHT SIDE OF HEAD ABOVE EAR (ABRASION, POSSIBLE CONCUSSION). DOCTOR RELEASED TO RETURN TO WORK BUT EE CONTINUED TO FEEL NAUSEOUS & FOLLOWING DAY DOCTOR ADVISED NO WORK UNTIL 6/8/05.