AN UNINTENTIONAL ROOF FALL OCCURRED IN AN AREA UNDETECTED GEOLOGICAL CONDITIONS. THE FALL MEASURED APPROX 18' WIDE BY 6 1/2' HIGH BY 120' LONG . IN THE #8 ENTRY INTAKE 60' IN BY SPAD #42430 AND EXTENDING 120' INBY. THE FALLING MATERIAL FELL ONTO TRAILER END OF THE UNIHAULER.