On March 4, 2023, a high speed intermodal crossed over the Illinois River just outside of Chillicothe, IL. As the middle of the train approached, I could hear an unfamiliar sound coming from one of the railcars. No, it was not a rubbing brake shoe or a bad wheel bearing. Quickly locating the weird sounding car, I noticed that it was wobbling abnormally on one of its bogies. It instantly reminded me earlier from that day when I had heard some radio chatter on my scanner about that exact train going into emergency. The crew said that they were not able to find anything when the conductor had inspected the train. After the train had passed, I went back to a safer spot where I would happily railfan the rest of the day.