A FALL WAS DISCOVERED WHEN TRACKING THE SOURCE OF A BROKEN WATER LINE. THIS ENTRY IS NEVER TRAVELED WHEN MAKING EXAMS. THE ROOF WAS SUPPORTED WITH 6' TENSION REBAR BOLTS. THE FALL OCCURED IN # 7 ENTRY N.W. MAINS 20' OUT BY SS# 2511. FALL MEASURED 110' BY 20' BY 10' THICK. A 6"" PVC WATER LINE WAS INVOLVED IN THE FALL. THE VENTILATION WAS NOT DISTURBED. WILL NOT BE CLEANED UP.