>In the US there is always a lawsuit and it's someone's fault

You can pretty much sue anyone for anything for sure, but there are big differences between criminal and civil law. A lot of cases come down to the "reasonable person standard" and what level of security should be inherently provided. Choosing to slide down a big crazy slide while standing up and hurting yourself probably fails the reasonable person standard, but choosing to slide down a big crazy slide while sitting and becoming injured because a piece of the slide breaks probably passes the reasonable person standard