First of all: very sad... my sympathy to the family... tragic...
If you go near chimpanzees, expect danger. Even if you are visiting some other chimp to wish him a happy birthday, nearby chimps may get jealous and attack you. Chimps are not people. They are animals -- dangerous animals. They may be able to communicate, think, use sign language, wear hats, and paint, but they are not to be blindly trusted.That is tragic and sad, but it is not entirely unexpected.
Here's Jane Goodall, talking about Gombe National Park in Africa (yes, it's out of context for this discussion, but it's nonetheless true): People can get too close. The danger is that chimps are four times stronger than people and they are becoming increasingly tense and more likely to become aggressive.
I await your vitriol at my unsympathetic rant.