I was on the other side of the world, stationed in South Korea. Obviously, it was night time (14 hours ahead) over there. I was on my way to bed, when I just happened to turn to CNN (with a fuzzy reception) to see one of the Twin Towers already smoking. I heard the reporters saying that they thought a small plane accidentally flew into the building. Several minutes later, I watched as a second plane violently flew into the other tower, and then I instantly knew it was no accident. That was probably the most surreal moment of my entire life.
After that, I tried calling back home to family & friends, but I couldn't get through, due to the congested phone lines. Eventually, I was able to contact people later on. So, about an hour or so after the 2nd plane hit, our battalion commander called everybody down to formation and basically explained everything that was going on. Needless to say, we were on the highest alert for the next couple of weeks.