^ Yes, please avoid those topics here in Haven.
That said, lucgn01, I'm glad your sister is okay.
I don't know how not to be bothered by it. It's scary when such things happen. I know, we've had our share of terror here in Europe which amounts to the same thing really. It's scary and it's easy to be paralyzed into inaction.
Likelihood is it won't affect you personally, but you never know for sure, because it also could. It's the luck of the draw.
You don't have to go to school the day after and pretend all is okay. It's certainly more than acceptable to be shaken up when people are killed just for living their lives.