there ya got me all excited, thought we had a new one! that was the johnson no.1 shaft subsidence. basically the cap failed on the several hundred foot open shaft. as the cap failed 2 of the 4 retaining walls failed as well and fell towards the center. they pinched against each other and held the cap up. now there was a big problem as they couldnt push it down or all the loose rock and dirt that the retaining walls were holding back would spill into the shaft creating a cone who knows how big. thats what happened back in the early 80s killing crane operator jerry white. osm was real cautious sealing this one, basically leaving everything where it was, filling on top and installing a new reinforced concrete cap over the entire thing. its covered with new dirt and grass but its near the ford dealership in the parking lot of a bank and behind the remodeled hoist house, thats easy to spot if you know what to look for. its repainted white and on a 45 degree angle to the road. it was directly behind that. thing that gets me is according to the maps and osm's boreholes there were 2 dry levels open before hitting the mine pool