A ROOF FALL WAS DISCOVERED ON 9-17-03 AT 10:00 AM BY THE FIREBOSS. THE ROOF FALL MEASURED 70' LONG BY 7' HIGH BY 18' WIDE IN THE #8 HEADING OF THE FORKMAINS SECTION, 4000 FT OUT BY THE SECTION AT SS #509. FALL DID NOT INTERRUPT OR BLOCK VENTILATION, NO EQUIPMENT DAMAGE OR NO INJURIES REPORTED. FALL WILL NOT BE CLEANED UP.