When I was going down there from 2010-2011 this area of land was roped off with caution tape (not the temporary kind). I was told when they had problems with their piping and had to drain down the pond to fix it, when they refilled it, they did so too fast and caused a sink hole here. I’m not sure what kind of info can be found on it since it is a military installation. Chris says years back he went down there and the docks were sinking, he was told there was a sinkhole in the pond, I think. A couple more pics of the area I saw to follow. I guess it was remediated.