Really confused at the people ethically equating the gorilla's life to that of the human child, but probably way more confused at the people absurdly claiming the gorilla wasn't harming the child when, no matter its intentions, if was factually injuring him and he was taken to the hospital afterward with "serious" non-life-threatening injuries. It's a 400 pound silverback - it's not going to know to consciously be more gentle, and there's no empirical evidence suggesting that it would not have further harmed the child if given more time with him.
Additionally, I feel that it's particularly disgusting and insensitive to claim that the death of the child would not have been a more negative outcome. The death of a curious four-year-old child - do you actually understand that? Can you contextualize that? I can't see how anyone could justify that by pointing fingers at the mother's so-called "inability to control her child."
We can talk about whether the situation would have been better had the mother physically removed the child from the vicinity immediately after he expressed desire to go into the enclosure - that would clearly have resolved the situation before it even happened, though I question proposing criminal charges for her. We can talk about other ways the situation may have been handled, but experts have suggested that attempting to tranquilize it could have further agitated it before the sedative took effect, risking the child's life further.
And while there is a chorus of expert and non-expert opinions on the situation, some experts with hands-on experience
are certain the gorilla was agitated and violent based on all the footage available and their expertise. There's relatively little evidence to show that the gorilla was, in fact, acting only to protect this child whose existence it became aware of only seconds before the video was shot - but again, even if it was, this is a 400 pound silverback with the capacity to injure or kill unintentionally.
Now, we can get into a more legitimate debate about animal captivity and the idea of zoos in general, and whether the current system is effective in any positive way for animals. We can talk about that and I happen to agree that entertainment-focused captivity is not beneficial, and can clearly lead to some very tragic incidents and situations. But we cannot say that - in light of the situation - there was any easy alternative to unfortunately killing Harambe. This is a tragic situation and it should not have happened for quite a lot of situations, but to suggest that there were alternatives seems to be incorrect according to experts and to the zoo officials with actual hands on experience, and to suggest that the child's death would have been an equivalently satisfactory alternative is just disturbing.