The question "where was God?" was well answered by saying he was with us, he suffered with us, and his compassion was demonstrated through us.
The question "why did God let this happen?" should be followed with a consideration on "what if he didn't let it happen?"
If God prevented the suffering of the innocent, it would then stand to reason that He condones the suffering does happen. Thus any suffering one person may inflect on another becomes justified and sanctioned by God.
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