I don't think it really matters whether either was an act of terrorism or whatever. The two were just on a completely different scale. How can you compare the loss of 8 footballs and a few journalists with the horror of 9/11 where over 3,000 innocent men, women and children (including babies aboard planes) died and many thousands more were seriously injured and millions of people, myself included were traumatised by the horror of it?
It's like comparing a dust-up in the school yard between Tommy 'Spotty' Higgins and Billy 'Sugar Ray' Bracegirdle at lunchtime with the battle of the Somme in 1916.