Engineers once shut down Niagara Falls’ water flow for three days
From Mashable (via AOL):
For several months in 1969, the torrent of water rushing over American Falls, one of three waterfalls that makes up Niagara Falls, was reduced to little more than a trickle.
American Falls is recognizable for the immense rock pile, or talus, at its base, the result of a series of natural rockslides over the years. In the late 1960s, concerns were growing that further rockslides could erode the falls completely.
To study the geological composition of the falls and forestall their potential destruction, a joint American-Canadian commission decided to dewater them for five months.