I was at work in CT, watching what I could on fuzzy antenna-signal TV, running back and forth to my computer to read the news updates, and wondering if my first cousin and best friend (and soon-to-be best man at my wedding 2.5 weeks later), who worked for Oppenhiemer Funds in Tower 2 was alive or not. As it happened, he left his cell phone on his desk on his way out of the building with a couple of preggo women from his office, not that having his phone would have done him any good anyway.
My wife's best friend worked for Amex at the time in the #7 building, but she fortunately called in sick that day (No conspiricists, she's not Jewish). We didn't know that either, though.
I left work and went home. A friend of ours who was freaked by the whole episode came over that evening and stayed the night with us just so he wouldn't be alone.