I don`t know if this counts, but here goes, back in the 90`s I rode a road bike to get into better shape for MTB racing, I was sucking wind at the back of the pack when we went around a corner to find that one of the guys that we were riding with had been hit by a car (OK, so maybe I was sucking wind so much that I got dropped to the second pack). It broke his pelvis among other things, and by the time the ambulance carted him away, not only was my knees shaking, but my stomach was tied into knots.
Did I mention that road bikes suck?