Does the coal mine exhibit still exist? It was a very long time ago, when I was a kid myself, something I have never forgotten, very neat.

The exhibit as a whole doesn't exist, but there is a nostalgia/tribute to it. It includes the "elevator" into the mine and a few relics and pictures. Took my kids through it last year and all they wanted to do was ride the elevator

It’s true - we have a nostalgiac coal mine elevator in our History of COSI exhibit in Progress.

I too remember that exhibit and loved it. I also have missed the "tribute" @Christopher White mentioned I will look for that next time I go.

Unfortunately, no. The coal mine exhibit no longer exists.