You might ask, how might such thing happen?
Well, the explanation is simple, let's just quote the boy's father:
"There was row of a few dozens of cars has stopped, and everybody went out of their cars and began photographing. My son went out to take pictures, as well. Then, suddenly, the hippo ran out to him, grabbed him by his leg and flanged him into the air..."Right...
It is not that there are about every few dozens of meters big signs telling in 3 languages "Do not leave your vehicles!". They probably should present them with pictures, just like in comic books. Writing in the man's mother language, apparently, just wasn't enough.
But wait there is more! Read what the man has else to say:
"Me and my brother in law, "jumped" at it pulled the boy. We fought it and threw stones at it, until it ran away. Usually I carry a knife, but today it wasn't on me. If i had it with me, I would have killed the beast. I've saved the kid, and luckily it ended this way. If it would grub him at the head it dragger to the lake, it would have ended with death."What a moron.
African hippo is one of the most dangerous animals in the zoo, and in Africa, hippos are accountable for more human casualties than any other animal. They are highly territorial and will defend their territory fiercely from any intruder.