Growing up as a child (I’m 48), it was get out of the house until supper, I have broken bones, bled from falls and stupid things (like running across picnic benches on benches stacked on their side for fall and winter), I am lucky I didn’t kill myself, but I was blamed for my adventures not my parents. But nowadays, if a child gets hurt, the immediate blame goes to the parent, and in this case the zoo. I agree with the author, it is very difficult to account for all dangers, and accidents are going to happen, and even the best risk assessment won’t mitigate some accidents.