Quite right. Every single one of 80 million-odd people within a certain border conforms with a stereotype which should render events like this impossible. They're in no way a bunch of individual human beings, potentially susceptible to the same mental fragility or perhaps bad influences as other person in any other country.
It's taken one man to do this. If you wanted to look at suicide rates amongst European countries you would find German higher in the list than us........ I think they are about 20th but none of that matters of course. One man, severely troubled if reports are to be believed or just plain evil. I know which one I would think more plausible.
We'll find out in the course of time.