delbows - my son was interested in 9/11 too I'm just not sure how healthy it is to know about these things at a young age. As a child I saw the pictures from Biafra and was really upset I remember. How could so many people starve in a world of plenty? There are big issues here, of equity and justice (and theolgy if you want to go there) and my viewpoint is probably/definitely skewed by my life experiences- do I want my son to have my political and social baggage? I don't know - tread carefully my friends.
Also ensure that your child knows that the real news is more than you see on TV - much more. i have long come to see TV News another branch of entertainment (cynically).
God bless us all in this awesome and bewildering job of guiding our little ones