A FALL OCCURRED IN THE #1 ENTRY OF THE 2 WEST TAILGATE. FALL LOCATION IS APPROX. 40 FT OUTBY SURVEY STATION 26 & 00. FALL IS APPROX. 5' HIGH BY 17' WIDE BY 10' LONG. AREA SUPPORTED WITH 8' RES IN ASSISTED ROOF BOLTS AND 12' CABLE BOLTS. ROCK FELL AROUND THE BOLTS THUS PREVENTING SAFE TRAVEL OUT THE TAILGATE ENTRY. CAUSE OF THIS SMALL FALL WAS BEAM FAILURE. COMPLANCE WITH RULES/REG.