September 11, 1916. Quebec Bridge (Canada)
This is not the first destruction of the bridge. The first time tragedy occurred in 1907.
About first collapse of the bridge
The bridge was nearing completion, when the local engineering began noticing increasing distortions of key structural members already in place. After four years of construction, the south arm and part of the central section of the bridge collapsed into the St. Lawrence River in just 15 seconds. Of the 86 workers on the bridge that day near quitting time, 75 were killed and the rest were injured.
About second collapse of the bridge After a Royal Commission of Inquiry into the collapse, construction started on a second bridge, but September 11, 1916, when the central span was being raised into position, it fell into the river, killing 13 workers.