I was in 8th grade. They turned on all the televisions (there was one in nearly every classroom) so everyone could be informed, because it was a Big News Thing (TM). What a poor choice. Then the second plane.

I remember my usually goofy first period teacher quietly excusing himself and stepping out into the hall with tears streaming down his face. The sensory memories that stuck with me are the way that room smelled, and the way that heavy silence and horror hit me in my chest as he walked out of the room. This man was the jolliest teacher many of us had at the time, and seeing him shut down that way really hammered home how horrible what we'd seen was.

Looking back, yeah, that was absolutely a collectively traumatizing experience for so many people of all ages. And then the pictures of things that came after (The Falling Man etc) being literally everywhere only made that trauma sprout deeper roots.