EE WAS INSTALLING THE FIRST ROW OF BOLTS IN #3 HEADING. AFTER HE INSTALLED HIS FIRST BOLT HE SWUNG HIS HEAD OVER & STARTED DRILLING HIS NEXT HOLE. HIS DRILL STOPPED UP (SUCTION) HE LOWERED THE HEAD AND TOOK DRILL STEEL OUT WHEN A PIECE OF ROCK 1"" THICK X 2' X 2' FELL AND STRUCK HIM ON RIGHT FOREARM.