Fall app. 20' wide, 20' long, 0 to 7' high. No injuries, no equip involved, no blockage of vent. Re-routed the smoke free escapeway around fall in #3 entry - which was also an intake. Fall will not be cleaned up. Breakered off & dangered & plotted on mine map. Was bolted with 6' tor. ten. and 8' & 12' cable bolts.