Roof fall occurred in the 6th subpanel south off of east 1st panel south (old #4). The fall began at spad #5 + 20 and was approximately 120' long x 18' wide x 6' high. Date of development 7/06. Type of roof support 6' fully grouted bolts. Cause of roof fall was due to the roof deteriorating above anchorage zone of bolts.