Well, this depends. First of all, I would have to suspend lack of belief, and assue the existence of God, heaven and hell. Done. Then I would have to accept that God killed only those children who were going to be corrupted and then not repent, and then not be forgiven in any case, and then go to hell. That seems unlikely, unless nuture in Sodom and Gomorrah led inevitably to unrepentant culpable corruption. There is also the problem that God, in his infinite justice, would save these children from hell by an early death, but not many others. How is that just? Then, even if this objection were overcome, I would have to accept that God sometimes intervenes and denies individuals free will, by killing them as children before they develop it. This seems to be not exactly aligned with Catholic tradition. And then, considering we are talking about a god who kills innocent children because of what their parents did, we would have to be sure we could trust him on the issue of heaven and hell. If he can be unjust in the treatment of the most innocent and vulnerable in this world, why would he be just in the afterlife? How do we know the children would not be consigned to hell?