EE WAS ATTEMPTING TO REMOVE AN OBSTRUCTION IN THE TRANSFER BIN TO THE CONVEYOR. WHILE DOING THIS TASK, HE ENTERED THE BIN WHEN HE EXITED THE BIN HE SLIPPED AND FELL 10 TI 11 FT. TO THE GROU ND BELOW. THIS AREA HAD LOOSE SHOT ROCK (10""MINUS) ON THE GROUND WHICH HELPED INFLICT HIS INJURIES.