History: Construction of tunnels behind Niagara Falls, 10 stories underground, before they were filled with water. January 9, 1906. [747x514]

https://i.redd.it/1g332iihdmr21.jpg via /r/HistoryPorn https://www.reddit.com/r/HistoryPorn/comments/bbyrtb/construction_of_tunnels_behind_niagara_falls_10/?utm_source=ifttt