I understand taking an animal out of the wild if it shows that it cannot survive on it's own. There is merit in protecting it.
These endangered animals should not be kept at the zoo.
There should be protected habitats, sanctuaries to keep these animals.
The mother is liable for child neglect in my mind, So is the father, and the zoo.
Besides the fact that the endangered animal shouldn't be there, it should be fully protected so that there is no way anyone can get close to it.
This animal died for no reason and the species' chance for survival died with it.