I was at work (in the Boston, MA area) and heard it on the radio - at first the radio announcer's were unsure also what was going on. Three of my coworkers traveled to NYC on AA that morning leaving Logan 1/2 hr. before the 1st hijacked flight left. My coworkers witnessed the bombing live. Shortly after the announcement, their spouses were calling the office in panic. It took a couple of hours, but we were able to located our folks (they had arrived safely to their destination in NJ).
I also could have been in NYC at that time. Two weeks before 9/11, I was asked to go on that same trip, for some reason I strongly felt I did not want to go, and told them I was going to pass on that trip.......