I have had conversations with several people about the lay out of the mining station so I drew a few maps for you:

The station layout in general: https://drive.google.com/open?id=12Wc4vimZnawkBHMmUCYVtY6OO-C5iUoL

The cross section view of the mine: https://drive.google.com/open?id=17LWRZRrQ2ZpBv5k4xBhmkYvCeX4D4Zgf

The top down view of the second floor where the miners are trapped: https://drive.google.com/open?id=1pyDvGQ5MFOVkynnE0MdrrFxQQ8zPK44L

GM Wombat