Hi Ed; I never worked in #22 or 27 Island creek mines, but did work in #7, which is the same coal seam, as the other two mines.All were declared "gassy" mines; no smoking, or open fires were allowed. # 7 never had any explosions.I'm inclined to believe the #22 mine exlosion was caused by bad ventilation problems.The air was short circuited, resulting in the terrible explosion that killed all those miners..A huge fan pulls the air from the main entry throughout a mine,so any gas is diluted, and harmless. Shelby ************************************** Check out AOL's list of 2007's hottest products. (http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001)