A ROOF FALL OCCURRED AT THE 200 OVERCAST AREA SPAD NO. 2-4 2B EXTENDING IN BY 70 FEET TO SPAD NO2-220. THE FALL MEASURED 20 FT WIDE BY 70 FT LONG BY 8 FT THICK. THE FALL WAS DISCOVERED DURING AN AIRCOURSE EXAMINATION THEREFORE THE DATE AND TIME OF OCCURRENCE IS APPROXIMATE.