A RIB BOUNCE OCCURRED AT STATION 19 AND 18 IN THE #1 ENTRY OF 14 RIGHT TAILGATE. THE BOUNCE BLOW A CENTER ENTRY 9 POINT CRIB OUT AND ALLOWED THE ROOF TO CAVE FOR APPROX 8 FT LONG AND THE ENTIR E WIDTH OF THE ENTRY. TAILGATE BLOCKAGE PLAN PUTINTO EFFECT AND MSHA NOTIFIED. TAILGATE STATION WAS IN BY 18 AND 75.