This is nothing new there are many places like that all over the US Tanners Lighthouse needs to get a life.
Washington DC
http://belowthecapital.org/
Underground city
http://en.wikipedia.org/wiki/Underground_city
When I was a kid it was fun to walk through the GM underground tunnel from GM building to the Fisher Theater building in Detroit.
Pedestrian Tunnel Connects Two Detroit Landmarks
http://news.yahoo.com/pedestrian-tunnel-connects-two-detroit-landmarks-172200169.html
Speaking of life; when yours ends, will you stay forever in GOD the Father's presense?
Are you a 'worthy' MORMON?
Will your family be with you FOREVER?