A 3-Way Intersection fell 8' - 9' high by 18' long by 20' wide. the area was bolted with 5/8 x 72"" fully grouted rebar with 6 x 6 plates and 5' x 13' straps. The area had been inspected 2 hours before the fall. It started to bow and work. The foreman reported it at 4 pm. It was dangered off and cribbed. The fall will not be cleaned up. Bad geology was the apparent cause.