I was in Mesivta. Came to the dining room after Shacharis and heard the radio blasting from the kitchen which was weird, but before I had a chance to think about it one of the Bochurim (who was not known to be bright) pounced on me and said that a plane crashed into the twin towers. I was like "yeah right" just as another Bochur said that another plane crashed into the Pentagon. I thought the second Bochur was making fun of the first one but then the radio finally filtered in and i listned in horror together with the rest of the boys as the first tower fell (I have to admit the thought crossing my mind at the time was, what will the skyline look like with only one twin tower). A second before Shiur a Bochur came running down the hall screaming the second tower fell. Now the R"Y was giving a Shiur as if nothing happened, I doubt there was a Bochur in the class who heard a word.
3 weeks later I took a flight home for Succos, there were 7 people on the plane: Me, another Bochur, some business man, a flight attendant, air marshal, pilot and co-pilot. As we were coming in for landing in LGA we flew along the island of Manhattan, I used to love coming in from that direction as the view of Manhattan is amazing. This time we saw all the smoke coming from where the towers were.