Gorilla killed

[Aroura]

So apparently,  that enclosure has existed as it is for almost 40 years without a single incident. No one else has fallen or even almost fallen in.  The enclosure is not the problem.

A small child managed to bypass all measures and get in.
This should not have been possible.
Kids are dicks and will do this sort of thing now and then. The fact the no one had done it before is not an excuse to carry out simple safety precautions.

Now if a fully fit 20 year old had managed to get in I would agree that it is possible for an adult to circumvent reasonably fool proof systems, but a toddler!

I disagree.  There are safety precautions in place, but the zoo does rely on people to also behave responsibly.  
I've read @15 people per year are killed at zoos.  Mostly handlers, but sometimes patrons.  In most cases the zoos re not charged, because they have adequate safety measures in place. Adequate does not mean foolproof not impenetrable.  

The only way to make it 100% safe is to not have the animals in the zoos in the first place.  Second would be full enclosures, but those went out in the 70's and 80's because they are unnecessarily cruel.  They still exist, but they shouldn't.  You see those primate exhibits where the animals face a wall all day?  Super bad.

if literally MILLIONS of people have passed by this enclosure without incident.  Other witnesses nearby claim mom was not paying attention to a child who was pulling away from her and proclaiming loudly he wanted to get into the enclosure. 

Kids ARE dicks, that is why parents need to be on full alert when at near an open enclosure with a 450 lb gorilla inside.  This mom apparently wasn't.

We cannot protect people from themselves entirely, no matter how hard we try.  There has to be a balance where some responsibility is given over to people behaving responsibly, no just being bubble wrapped everywhere they go.