The Spanish River derailment was a rail transport accident that occurred on 21 January 1910, on the Canadian Pacific Railway (CPR) Webbwood Subdivision, where the railway crosses the Spanish River near the settlement of Nairn near Sudbury, Ontario, Canada. A westbound passenger express train derailed and crashed into the Spanish River bridge, killing at least 43 passengers, though the death count varies. The cause was never established, but was believed to be poor track condition and/or speeding and braking on a curve.