When the underground came about, it was basically a raising of the streets to thwart the daily tidal surge off Puget Sound that was flooding the city. Everything imaginable was used as landfill including trash, broken wagon wheels and horse remains. When the project was finished, the first floor of this building was under ground but still operable. Quite amazing feat, actually.
Seattle Street Photo Pre-1900
From Pamela Wiggins, About.com
This photo shows what Seattle looked like prior to the underground.
Seattle prior to raising the street level
-Pamela Wiggins©2009 About.com, a part of The New York Times Company.
All rights reserved.