I remember being told that it would be for our generation analogous to the Kennedy assassination: “Where were you on 9/11?”
I was a senior at Thomas Jefferson High School for Science and Technology in Alexandria, Virginia, eight miles from the Pentagon. Some students who happened to be outside, attending PE class or perhaps arriving late and still parking their car, claimed to have seen a plane flying unusually low. I was signed into the library during first period because I enrolled in online statistics with a former teacher who had taken a position at Cal Tech. The first thing I remember was one of the librarians turning on the television a few minutes before 9am; slowly, more and more people gathered around the image of the smoking North Tower. We watched in silent disbelief as the second plane plunged into the South Tower.
Things get fuzzy after that. I remember going to my other classes (geosystems, whatever I had during fifth period, government), but it was like attending class on the last day of school: nothing is taught; no one is focused. I don’t remember when we heard about the Pentagon, whether it was a circulating rumor or a formal announcement over the intercom. Secretary phone lines were being used to call family and loved ones. I felt shaken seeing some of my usually stoic peers in tears, frantically trying to get a hold of their parents who worked at the Pentagon, before cell phones were widely used. I had a bulky car phone that, thank God, was actually working that day, and I was able to get in contact with my dad who had received word that my brother in NYC was evacuated and safe.
Field hockey practice (like all after-school extracurriculars) was canceled, and Ashley and I drove straight home after last period. I remember feeling taken aback by how clear the sky was, how empty the roads were, and how some radio channels still bothered playing music at all.
I believe only one TJ student, a freshman at the time, had a parent who was killed on September 11th, 2011; he was on the flight that crashed into the Pentagon. A lovely service was held for him at Arlington Cemetery in February 2002.
Today my heart is with the loved ones of those who perished due to the attacks of September 11th, with the cities of New York, Washington, D.C., and Shanksville. I can’t believe it’s been ten years.
anna in med school 
I remember driving back with you so clearly. I had no way to get home and you took me in! Remember my dad telling us not to stop anywhere (convenience store, etc) because the chaos of that day created an unparalled opportunity for someone to rob a store and get away easily? Such a strange time that was.
Of course I gave you a ride, it was never a question. You were someone I wanted to be with very much, and you would have done the same. I do remember very clearly your dad saying that and being glad that I had filled up the day before.