Magliari says five of the train's 63 passengers were treated at hospitals for minor injuries. Amtrak gave the rest of the passengers the option of going onto Chicago on charter buses or returning to St. Louis.
Magliari says it's not yet known what caused the two cars to leave the tracks. The train had two locomotives that were pulling five coach cars.
The railway is owned by Union Pacific and Kansas City Southern. The track owners and Amtrak are investigating.