I remember seeing a television news special about this. I guess Portland was one of the worst cities for this. One bar had a trap door under a bar chair. One yank on the door, and you were shanghaied. Lots of people went missing during the late 1800's and early 1900's. Most people don't know that there is a whole city under the city.
Yup, Seattle also. Pendelton, OR has tours of their tunnels.