> The people that drew up a potential target list did so years before

And the building was a military installation years ago. Then Iran made it into a school, nobody is omniscient here, collateral damage will always happen in war.

If things stayed static and simple as you think they are, if Iran let US military spies freely go around and note targets, or if Iran updated USA when they move their military ops around, sure collateral damage would easily get avoided, but the situation isn't like that.

> The people that decided to fire missiles are the people that decided to start a war by firing missiles .. during negotiations no less.

No, the people who made the target list are not the same people who started the war. Trump isn't there picking which building to fire it if you thought that, its guys much further down. Nobody said "we want to kill a bunch of schoolchildren first day!", they tried hard to avoid such events or many more would have died, but you can always do more and its a tragedy that it happened once.