Riding the Nicolet National Forest (WI) Roche Trail for the first time I was trailing my friendby about twenty yards headed down a fairly shallow hill. Neither of us realized that there were a couple man made log towers on that section. Nothing huge, no more than 10in tall. But my buddy was even less experienced than I was and he kind of freaked and slammed on the brakes when his back tire left the ground over the first tower. he did an endo and ended up laying on the trail on the down side of the log pyramid so I had to slam on the brakes to prevent from running him over. I did an endo over the top of my friend and landed further down the trail. When I turned around somehow he ended up completely under his bike, holding the frame up with both arms. I made him stay there while I took a picture it was so hilarious.