http://www.straitstimes.com/world/united-states/us-zoo-kills-gorilla-after-boy-falls-into-enclosure
Though it will be taken up sensationally, we must think about another case. For example, if the boy had been killed by the gorilla, the zoo would also be blamed.
So, the zoo was destined to be blamed, once the 3 years old boy crawled into enclosure.
The zoo will have to take measures for keep observers away from enclosure.