I was in college on 9/11. If you weren’t old enough to know what was going on, it’s impossible to communicate how much of a “spectacle” it was. The closest I can come would be to say imagine if you woke up and aliens landed on earth. It wasn’t just that everyone was glued to their TVs set. It was just this… thing that was happening. In my dorm, everyone just watched it on their TVs alone. Got lunch with my friends and no one spoke hardly at all. Just a completely surreal day that’s hard to describe to anyone who didn’t live it.
Edit: to further emphasize the “spectacle” part, later in the day I had to run an errand with a friend. On that drive he confided in me that “I kinda want to see the number [of dead] go a lot higher”. He wasn’t saying that because he wanted a reason to start a war. And he wasn’t some weirdo. He was a very thoughtful, empathetic person (but brutally honest about things, like Jan Maas in Ted Lasso). I think a TON of people felt that way but didn’t say it out loud. I don’t buy that people were traumatized that day or anything. I think they were captivated by the spectacle and were mad that our collective ego was bruised, and didn’t really care about actual dead people.