17K views · 1K reactions | Seattle’s underground was an unintended consequence of regrading the streets after the great fire. Tacoma’s underground isn’t the same story though, their’s is an intentional underground designed to help terrace the city up the steep hill. The vaulted chambers beneath the sidewalk help with grading and flood prevention. #wa #history #pnw #tacoma #seattle #underground | Pretty Gritty Tours | Facebook