18 years since then
I had only been in the United States for 2 weeks or so. 1st day of high school in New Jersey trying to figure out why a bunch of kids kept on using the word "lockdown" with the little English I could understand then. I can remember asking what's going on with the little English I could speak then. One of the security guards telling me "you do not get out unless we tell you".
Walking up the stairs to what should have been my 1st class ever in this country only to look out the window at what seemed to be darkness falling and spreading over the horizon. As I was sitting at my desk wondering about about what I saw, this teacher standing at the front of the class with a confused look on his face tried explaining more things I could not understand yet I remember being able to feel the weight of it. And the day went on with "regular" classes until we were allowed to leave and go home.
Eventually in the evening my sister explained that the place I could see in the horizon was New York City and the darkness was smoke from fire and debris... Planes had crashed into the Twin Towers of the World Trade Center. I remember feeling a sort of sadness I had never felt before and saying to myself "how can this happen in a country like this one?!".