What ever you do, don't tell them that adults have fears. That might make them concerned about the safety of their future.
I have fears. I fear for what happened to those people who fell out of the windows. We saw photos and video of such attrocities but never saw any bodies. Don't Americans bleed? When Palestinians blow up Israeli families, there are images. When we hit civlians with an errant missle, there are images. Our deaths were kept to a dwindling statistic.
If is considered to be in "bad taste" or overly "graphic" to show them such imagery (even just the collapsing buildings and screaming people) then why do they still show images of victims of the Holocaust 50 years later? Aren't the stories and that statistic of 6million enough to convey the severity of what happened?