The International Railway Bridge is a two-span swing bridge carrying the Stamford Subdivision of the Canadian National Railway across the Niagara River between Canada, and United States. It was originally built in 1873 for the International Bridge Company by Casimir Stanislaus Gzowski and D.L. MacPherson. The bridge consists of two sections, the first extending from the Canadian shore to Unity Island and the second extending from Unity Island to the American mainland shore. The portion between these was originally built on a trestle, and was filled to form an embankment soon after the bridge opened.
1 year after people: Abandoned ships on the Great Lakes drift towards the Niagara Falls but are stopped on the Niagara River by the International Railway Bridge. The bridge does have an enemy however, ice became a problem in the time of humans. Now that there are no humans to deploy the boom, ice and ships begin to assault the bridge.
20 years after people: The International Railway Bridge is blockaded by several washed up boats, brought in from their failed riggings and the continuous winters. Thankfully, the boats provided a solution of ice crashing towards the supports, but this wouldn't last long. After 20 years of constant winter storms and the boats bombarding the rusted structure, a ice flow pushes the boats to the bridge's breaking point, and one final push causes the entire span to fall into the river, opening up the way to Niagara Falls.