On June 29, 1864 a Grand Trunk train carrying between 354 and 475 passengers, many of them German and Polish immigrants, were travelling from Quebec City to Montreal.
At around 1:20 a.m. local time the train was approaching a swing bridge known as the Beloeil Bridge on the Richelieu River. The swing bridge had been opened to allow the passage of five barges and a steamer ship. A red light a mile ahead of the bridge signalled to the train that the crossing was open and it needed to slow down. However the light was not acknowledged by the conductor, Thomas Finn, or the engineer, William Burnie, and the train continued towards the bridge.
At 1:20 a.m. the train came onto the bridge and fell through an open gap. The engine and eleven coaches fell through the gap one after another on top of each other crushing a passing barge. The train sank into an area of the river with a depth of 10 feet. 99 people aboard the train were killed and 100 more were injured. Among the dead was Thomas Finn and the fireman aboard the train. The engineer was slightly hurt in the accident but was able to escape the wreck. The disaster was blamed on the conductor and engineer for failing to follow the standing order to stop before crossing the bridge. The engineer, who had only recently been hired, claimed that he was not familiar with the route and that he did not see the signal.