I also wish to offer my support to people affected by this tragedy.
When a calamity happened during my Naval service there would be a Stand Down to focus on remedy.
It seems like a good time for us as a society to do a little navel examining and ask ourselves what makes people do these tragic things. Might I suggest viewing Bowling for Columbine. Whatever opinion one has of Michael Moore, I think that movie is profound. I also recommend The Art of Happiness At Work by the Dalai Lama.
While working in the school system I got a close-up look at the stresses people put on each other and the kind of damage that can happen when a person has no defense or support mechanism to help us cope. We don't know much about the gunman, but I can guess a few things.
My boss remarked that as a society we seem to be losing our
caring. I think he's on to something. In his book the Dalai Lama mentions the degree to which people (managers for example) should care for others, as in taking on some responsibility for their well being. I referenced that in my paper on following procedures.
In the end we have our own peace to maintain, responsibility to be fair to people near us and our ability to look at matters in the context for improvement.
I hope we can all come away from this with some of these things.

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