On the 29th of June, 1864, a train in Quebec, Canada fell through an open swing bridge and into the Richelieu River.
The worst train disaster in Canadian history, it is thought ninety-nine people died in the crash. The majority of people on board were European immigrants.
The investigation placed the blame for the disaster on Grand Trunk Railway, as the train failed to acknowledge stop signals that would have prevented it from falling through the bridge.
In Times Gone By... 
Uf! Scary! I hate bridges…
You can say that again.
And it was such a silly mistake that caused it.