The image that got to me was a photo-realistic portrait by a gentleman named Alex Ross (I think his website is alexrossart.com), of Superman, probably the most iconic figure in all of comics, gazing up at a picture of policemen, firemen and EMTs against the background of the fallen towers, with the single caption "Wow."
Beyond that, I've bought and read perhaps a half-dozen collections interpreting the events, either within the "lives" of of the heroes I love, or by the artists responsible for creating them. Since so many of the people who make comics in the US live in New York, there are hundreds of powerful, genuine stories and images coming from that.
Daily comic strips had their moments, too. Daily comics are ephemeral, but those that came in the days and weeks that followed were very memorable.
I'm a big fan of sequential art. It is a form where an Icon really can rise fully to its meaning.
And prof, I wouldn't worry. The meaning here of 9/11- at least where I'm sitting - is not revenge, but of tragedy and loss, heroism and sacrifice. Many, many powerful symbolic statements came after but none so far appear to be spiteful.