Most of you probably have powerful recollections (I'm already beyond sad to hear about Roxy losing her friend), so I'll try to keep my story as humble as it truly is, but I can assure you I still remember the shock of seeing it almost all live on TV.
I was in 6th grade and arrived home from school (must have been those weird years in which school started on the 1st of September here, instead of the 15th), I'd say around 3:30pm (8:30am NY). I didn't turn the TV and landed on CNN until after the first plane hit, but from there onwards I watched everything unfold. I was even alone for a while, my parents came from work an hour or so later. At first, for a second, everyone thought it had to be some kind of TV stunt or trickery, but then it sank how very real it all was. My parents were tired and had to take their usual rest, but I kept watching and even recall waking them up when the second tower collapsed. In retrospect, I'm not sure how good it was for me to (be left to) watch, but that's a different story. The media coverage was pretty much non-stop, not only throughout that day, but for days to come. I didn't see any jumpers (the only image of that I have in my head is from reading Jonathan Safran Foer's Extremely Loud...), like G-Man, but I saw footage of people running from the debris cloud and such.
The day after, everyone in class couldn't focus on any actual lessons. Teachers were either rambling or sighing in disbelief and we were talking with each other about what we did or didn't see. I'm afraid I wouldn't label ourselves as being too well-mannered, rational and empathic debaters - on the contrary, we tend to be very gossipy, conspiracy-addicted or simply loudmouthed; tabloids with "can you see the face of the devil in this plume?!" articles were already running on the second day after the attacks - then again, we were kids, it made a great impression on us and we needed to talk about it.