Well people tend to be stupid around animals, they think they are safe because they are in cages and that they look so cuddly and cute, but polar bears, lions etc can reach through and when they grab they don't let go easy.
Wasn't someone grabbed by a tiger or something a few years ago and dragged into cage. I vaguely remember something like that happening and an incident with an ape/guerilla as well.
With my luck I would fall into a penguin pond and be chewed into little bits and bites a little bit at a time to death. ha ha I do love seeing the penguins though, they are my favourite animal. I wish I could have one as a pet.