Tacoma's Tunnels & Caves

I go out of town for a few days and guest editor Jamie starts getting busy on ThriceAllAmerican.  Of particular interest is his exploration into any details regarding the old tunnels beneath Tacoma.  I’ve seen a few passing references to these tunnels (and cave netwokrs), but haven’t been able to find any information recently.  Jamie seems to have done a lot more research than I have on the topic and I would curious to know what you might know.  Any insiders?

Link to Thrice All American