Sensless violence. I would say "The only positive from this is he took his evil out of this world by killing himself". But, I do not like death. Even if he did "deserve" it. I feel its not my place to say that, or enjoy it.
So many families were torn apart. So many lives were crushed. Its all so heavy. Why? Why would someone do such a thing? It is a mystery what drove him to do all this. But killing children, your mother, brother, innocent teachers trying to protect their students, and then yourself? That suggests to me a tortured soul. Deeply disturbed and deeply unhappy. And, had it been he only killed himself, I'd feel bad for him. But due to him killing so many innocents.... its very hard to.
Lets remember the victims, the families and the brave teachers.