EE WAS CHANGING HIS BLUE AIRLINE ON HIS EQUIPMENT USING 2 CRECENT WRENCHES. THE CRESCENT WRENCH USED TO STABILIZE THE TOP NUT WHILE TIGHTENING THE BOTTOM NUT FROM AIRLINE TO GLADHAND SLIPPED O FF THE NUT STRIKING THE EE IN THE BOTTOM LIP SPLITTING IT OPEN - REQUIRED 2 STITCHES.