A GROUND FALL OCCURRED ON 2475 LEVEL ON M1 DRIFT BTWN X-17 AND M19 LX DRIFTS. ROOF FALL APPROX. 4'W, 4' THICK AND 10' L HAD FALLEN DURING THE WEEKEND. THIS AREA WAS PREVIOUSLY ROOF BOLTED, W IRED AND GUNITED. DIKES & STRONG JOINTING ORIENTATION OF THIS AREA PROBABLY CONTRIBUTED TO THIS ROOF FAILURE. AREA WAS BLOCKED AGAINST ENTRY UNTIL IT WAS SCALED AND STABILIZED WITH SPLIT SET