Last year when I was 11, I was on the swing at my school and I was swinging super high, like 12 feet up. Not to my knowledge, the ring in one of the sides of the seat was twisted, leading me to leave school later on by these events: I swung higher than before, and the chains beside me lowered, and the seat began to fall out from under me. I hear the swing's chains jerk just before I hit the swing, and I expected to be caught and easily start swinging again, but instead I hear one side of the swing pop, and falling to the ground at high velocity - about the speed of a car down a local road, about 28 miles per hour, my butt smashed into the ground, and I felt a shock through my body, and my abdomen instantly went numb. I looked at the seat to my left, and the rubber ring at the end of the chain to my right, and realize that I am in big trouble. For one thing, my teacher didn't want anyone above the third grade swinging. Another thing is that she particularly made sure that I acknowledged that, because I'm about two years older than my grade level. Another problem is that I did it on the one day that she was absent - a clear sign of deliberate disobedience. I got checked out of school a few minutes later, and by then I was hurting horribly, and it only got worse. I had to put ice on it, and I took some tylenol, so it stopped hurting a little bit, but I was really sore for the next few days.
And now, one year later, I am banned from ever swinging on that swing again.
tl;dr: I wasn't allowed on a swing. I swung on it. It broke. My butt almost broke and I almost sheared my growth plates off completely.