Crews from CN Railroad and Amtrak were kept busy yesterday working to determine what caused an Amtrak locomotive to go off the rails just east of the 24th Street viaduct. Reports say the trailing locomotive derailed shortly after leaving from the Amtrak station on 16th Street at around 6:20 a.m. The train was headed toward Chicago. Shortly before noon Wednesday, crews were able to disconnect the trailing locomotive from the rest of the train, which then continued on to Chicago. There were no injuries among the fourteen passengers on the train. Officials say trains will continue to run between Port Huron and Chicago while the derailment is under investigation.