THE ROOF BOLTER OPERATOR HAD JUST FINISHED DRILLING WITH THE STARTER STEEL. AS HE LOWERED THE DRILL MAST TO ADD AN EXTENSION STEEL, THE WRENCH STRUCK THE STEEL ROOF MAT, RESULTING IN A SPARK W HICH IGNITED METHANE. THE FLAME WAS EXTINGUISHED USING ROCK DUST AND A 20 POUND FIRE EXTINGUISHER. NO INJURIES OR PROPERTY DAMAGE OCCURRED.