As a second thought, I'm not trying to implying anything here. As a believer of Karma, I think most people, once they have kids, they would less likely to do harmful things intentionally to others in order to avoid any kind of retribution. Cos, there is a belief that if you do something bad to other people, bad deeds will come back to haunt you or your kids. Nonetheless, even if we don't do bad things to others, bad things can still happen to our kids. Cos, for believer of karma, most of us believe in reincarnation as well. So, we may did bad things in our past life that could cause payback this life. That's something we can't avoid. Also, even if we didn't do any bad things in our past life, our kid might have done bad deeds in his/her past life that could come back to hurt him/her this life! Certainly, we wouldn't know what happened in our past lives and even if we do, we can't change that. So, the only thing that we can do is to make good deed and don't do bad things in our lifetime.
With such attitude and belief, as least that can help us to make some senses of why certain unfortunate things happen to superficially Innocent people and would help to make it relatively easy to accept their happenings. That didn't take away the pain and sorrow for tragedies. However, once the emotional part is fading away, the logical sense will kick in in higher gear. For folks like me, logic does help, though we may never know the truth.