OPERATING CONTINUOUS MINER IN COAL FACE, MAKING THE RIGHT SIDE CUT THE MACHINE HAD PENETRATED APPROXIMATELY 15' DEEP WHEN HE OBSERVED SPARKS NEAR THE MINE ROOF. SUDDENLY PAIN WAS FELT TO HIS LEFT ARM. THE CUTTING BITS HAD CONTACTED A SULFUR BALL NEAR THE MINE ROOF. A SLIVER OF STEEL EITHER OFF A DRUM BIT HOLDER OR CUTTING BIT BROKE AWAY, FLYING BACK AND STRIKING HIS LEFT FOREARM.