My prayers are with those dear people affected by it. I cannot imagine what they are going through, but thankfully there is a God who does. It's a sad world we live in, but how comforting that we can have hope in Christ, who is able to give unimaginable comfort amidst unspeakable evil.
I gathered here some links, sources of encouragement and comfort that I hope you will find helpful.
Weeping With Those Who Weep, a great article written by our friend Joey who is a pastor in Newtown.
An insightful commentary, Rachel Weeping for Her Children, by one of my favorite preachers, Dr. Al Mohler.
A Pastoral Response to the Newtown Massacre, a 5-min audio by Dr. John MacArthur
Safe in the Arms of God, an excellent book that offers biblical comfort to parents grieving the loss of their little ones.
Every day is a gift from the Lord. Hug your precious kids a little tighter and a little longer. I know I do!