It was the twin towers for me too!
I was at work when a mate in the office called me asking could I find out as no-one could get any response from the internet. I ended up in the Boardroom with the TV on. Various people popped in to see what was going on. At one point, a manager was watching with a few us and commented about how he could see one of the towers swaying and reckoned it was going to fall. We were in the middle of questioning him about how could he see that and how they wouldn't collapse when.....! :-(
I also can remember that day when the plane went into the second tower and it was live on TV. The news had just shown a replay of the first plane hitting and although the picture clearly stated "Live" in the corner of the screen, the news anchor was saying how we were seeing the replay again. But you could tell in their voice they didn't believe it, but I think couldn't quite comprehend what they'd just seen!
