Something really scary for me was, my dad works for the government. At the time, we were living right outside of DC. His office was across the street from the Pentagon. At the time though, my dad was in NYC for work.
My uncle's office had a window that looked exactly at the Pentagon, he saw the plane and the explosion. Obviously with my dad working across from the Pentagon, we had a lot of family friends in that general area. It was kind of scary not knowing how they were. It ended up that my uncle went over to the Pentagon and helped them over there.
As for my dad, He left for NYC Sunday Sept. 9th. He was supposed to stay at the hotel in the WTC or around it, I'm not sure, I believe it was in the trade center. At the last minute, their plans changed, and they got transferred to a hotel closer to the NYC DEA office. They ended up being about 5 minutes from the TC instead of right underneath it. 
I had so much family in that city too, just scary. It's still hard to believe that they haven't even started the memorial. I'm all for the Freedom Tower. I love it, I love the idea, but in a way, I think it's giving terrorist another opportunity.