At an AKC trial, Kal was the first dog to run. I did not notice that the tire wasn't staked or sandbagged down. He misjudged the tire (it was the first obstacle), it hung up around his middle and the whole thing fell on top of him. I did not know until I saw the photos (well after the trial) that the frame had hit him on the head. I'm glad the frame was PVC and not metal... He suffered no ill effects, and the judge was kind enough to let me put him right back through the tire once it was righted. Video of this is located at http://www.youtube.com/watch?v=uP9cLQVzViU