Hi, in my opinion you aren't heartless.
I agree with the ones who said that "If we felt everything that's ever happened, we wouldn't be able to go through life."
But I would like to add something, the most important thing isn't being heartless; the most important things is not forgetting what did happen there. Everybody won't feel the same, but everybody must know what it did happen there, because if we know that and we remember forever, we won't do as horrible things as the ones which were in the concentration camps...Believe me, the most important thing: don't forget the history. Thanks, it's a very good post for talking with good people.