That brings back memories. My dad had a red and gray Ford tractor. My sister and I would ride on the fenders. One day we were on the fenders and he was pulling discs on the back. We were headed to a field, I suppose. He hit a bump and my sister and I went flying. He caught my sister, who had tire burns across her chest. He couldn't get me in time and I ended up under the rear wheel. I remember being under the wheel and looking back at those discs. My next thoughts were of the look on Dad's face as he was running, carrying me to the house. He was yelling at my Mom, "I've killed her, I've killed her!"
I was fine. My pelvis must have taken the weight. Rubber bones I guess. My sister would have surely been crushed.
None of this may make logical sense. It's my memory of the incident after 55+ years.