When I was a kid, maybe 8 or 9 years old, while at the fair one night with my father and step-sisters, I fell against the canvas walls of a fun house after traversing the moving stairs and slid under the structure. No one saw me fall and no one knew where I was when I wound up under the fun house laying on pipes and pavement. Adults were relieved to find me after a few minutes and I was grateful to get out of that dark and dirty place. No permanent injuries, but now avoid walk-through fun houses. Also, it was in the day before lawsuits for such a thing.