I feel like people who are totally blown away that a child could get away from an adult in a busy area like a zoo have never interacted with a child in zoo... Or anywhere.
It was probably negligent on the parents part.
It was probably negligent on the zoos part.
Sometimes smugly blaming people for things that happen and implying you think a child deserved to die because of it's own actions or the actions of others isn't actually that helpful or clever.
A child fell into a wild animal's enclosure in a zoo. I think it goes without saying that someone fucked up. A mix of the zoo and the parent, as you say. However, as all the other adults that were responsible for a child managed to avoid having them fall into said enclosure, one might suggest this particular adult was particularly foolish.
Did the animal deserve to be killed because it had the potential to kill the child? Probably not. The first thing the zoo did was to kill the animal, though. A bit unfair that someone else's fuck up results in that.
Also, unless you're referring to Yoink, I'd appreciate you not putting words in my mouth, maaan.