St. Paul police are in the process of planning security for a vast underground network of caves and man-made tunnels underneath downtown St. Paul, tunnels they say could pose a security risk for the Republican National Convention in September, according to KSTP.
The cave and tunnel system, dubbed “The Labyrinth” by spelunkers and urban adventure enthusiasts, runs through the sandstone and limestone bedrock upon which St. Paul is built. According to research conducted by American Engineering Testing, Inc., during the testing phases for the Excel Energy Center, the cave and tunnel system is largely man-made:
“The tunnel story starts in downtown St. Paul in the 1840s, when the city began to carve a network of utility tunnels into its underlying sandstone bedrock. These subterranean structures usually followed the streets above, and offshoots or drifts extended to the buildings along the streets. As time went on, this system grew to be a complicated maze with more and more drifts constructed in order to service buildings. Tunnels are present under most of the downtown area, are often many stories deep, come in all sizes, and are in various states of repair.”
The Minneapolis Urban Adventures Action Squad, an urban exploration group, has mapped and photographed much of The Labyrinth and has a comprehensive description on their website. The tunnels include old transit ways, telephone, gas, water and electricity tunnels, abandoned sewers and Prohibition era tunnels.
St. Paul police said they will be following the lead of another city with extensive tunnel systems — Boston, which hosted the Democratic National Convention in 2004.
“It wasn’t a surprise. We’re not the first. We were able to look at what Boston did too and secure those access points,” St. Paul Police Assistant Chief Matt Bostrom told KSTP. “Because the international media lens is on us, we cannot afford any missteps,so from a security standpoint we really have to do our homework.”