I was working in WTC 4 (one of the smaller buildings in the complex) and was at my desk early. The first plane sounded like an in-bound cruise missile and shook our building, which was across the plaza from the North Tower. By the time the second plane came, we were across the street at the Millennium Hilton. I was looking up, and saw the second plane as it was turning on it's side just prior to impact. Once it hit, pandemonium broke loose. I went out the side of the Hilton, around the corner ... I was staying with my back close to the building as there was big debris raining down, and I headed down the subway stairs - luckily an uptown train was just arriving. I remember telling folks not to go outside and just get back on the train. Of course, nobody was going to listen. I remember standing during the subway ride up to Penn Station, almost numb...another woman who just got on with me was visibly shaken, hysterical in tears.
When I reached Penn Station, I quickly jumped on the first NJ Transit train heading out. I was lucky, because all the train lines were shut down shortly after. My heart finally stopped racing when the train exited the tunnel on the NJ side of the river. I didn't have anything with me, other than what was in my pockets - my wallet and car keys. Someone was nice enough to lend me their cellphone so I could quickly call my MIL, since DW would have been on her way to work already.
I was a bundle of nerves driving from the park and ride lot back to our house, and finally felt some relief pulling in to our driveway. DW was still there, alerted to what was happening, just wanting to see that I made it home. We then went and picked DD up from school as fighter jets were buzzing overhead (about 30 or 40 miles outside the city).
Anyhow, here's my colleague's post from that day:
https://tinyurl.com/rj26vxbr