I'm sorry, but I don't buy the "God's Will" thing. I respect their faith, but I can't believe God would will such a thing.
God does not will any of us to suffer. But you have to understand something: we live in a fallen world. A world where our sins have separated us from God.
It wasn't supposed to be this way. But we turned away from Him.
His presence has not left, moreover, He has given us all a way out. This is where Christ comes in.
God did not spare Job either. Job was a man most favored by God, but in one day he lost his possessions, his business, his home, and his family. Then he lost his health.
He asked God "Why?" God gave Job an answer, but not to the question he asked.
I will leave the "Why" up to God. We are not Him. But take heart - Christ said that not two sparrows fall to the earth without God knowing about it, and every hair on your head and my head is counted.
He cares, and loves us more than we can ever imagine.
Death comes to us all. Those innocent little girls are in His arms, forever, in paradise. The man who murdered them is in Hell - in torment forever.