THE EMPLOYEE WAS WALKING ALONG THE SOUTH SIDE OF #1 GATHERING BELT. A PIECE OF GRATING THAT THE EMPLOYEE WAS STANDING ON DROPPED OFF OF ITS SUPPORTS. THE EMPLOYEE FELL 11' ONTO AN UNCLINE OF H ARD MUD AND ROLLED OR SLID ANOTHER 9' TO EXIT. THE BIN AND THEN FELL ANOTHER 3' TO THE GROUND LEVEL AND LANDED ON TOP OF SCREENINGS.