The Louisville area, and perhaps Rock Creek, are well know for their coal mines. Mine shafts collapse and take houses with them. It is not unheard of in that area.

I just had Olshan put pilings under my foundation because I had a problem with expansive soil - i.e. reverse espansion (contraction). The severe drought we had a few years ago took water OUT of the soil and my foundation gave way. With Olshan, you should budget about $1400 per piling. I needed 5 of them.