It is totally unimaginable that any living thing could do this.
I find it unimaginable too. But for all that, there is nothing unusual in it. Hiroshima. Nagasaki. Dresden. Hamburg. And the list could go on a lot longer, and it is all that likely to get longer still.
All we need is to believe that this is something that we need to do and are entitled to do as a way of balancing some atrocity that "we" remember and "they" ignore. And that is the way a lot of people seem to be thinking today in the wake of yesterday.