PHOTOS: When a tunnel was uncovered during the demolition of Dexter’s former fire station, it set off a wave of speculation and excitement among residents. Standing about 7 feet tall and ending at a bricked-up wall, the tunnel’s purpose wasn’t immediately clear. Whispers of secret passageways, bootlegger tunnels, and the Underground Railroad quickly surfaced, adding an air of mystery to the discovery. In the Friends of Dexter Facebook group, residents shared theories ranging from the playful to the historic.