Yes. My sister watched it unfold in front of her eyes from her office in the Financial District, while an office mate and her tried pulling a sobbing puddle of their co-worker off the floor when the first tower, where her fiance worked, collapsed (he called soon afterwards to say he got out all right).
My long term girlfriend was working in the city government office in Alexandria.
My father regularly flew USAir flights out of Pittsburgh for business. It took some time before I learned the plane that crashed in Western PA wasn't coming in or out of Pittsburgh.
I was working in a government office skyscraper, albeit in Ohio.
The stress was.....quite bad. And then I heard 3000 dead.
Though I was alive and have vivid memories of 9/11 myself, it's hard to watch the footage and know that only (as awful as it was) 3,000 people died. In the hours after the attack I remember people thinking tens of thousands were dead.
It wasn't just the first few hours. Even the next day, weren't people estimating that it was something like 6000? IIRC, it took weeks before the best estimate of the number of fatalities went as low as 3000.