EE WAS ROOF BOLTING ON THE FLECTHER BOLTER RIGHT HAND SIDE. HE WAS RAISING THE BOOM WITH THE STARTER STEEL IN THE DRILL CHUCK. HE HAD HIS HAND ON THE STEEL AS IT TOUCHED THE ROOF. THE STEEL WA S NOT ROTATING. A PIECE OF GREY SHALE FELL & HIT HIS RIGHT THUMB. HE FINISHED THE SHIFT WITHOUT ANY PROBLEM. AFTERWARD HE WENT TO THE E.R. WHERE X-RAY REVEALED A BROKEN THUMB.