Somewhere I have the photos of my trip in the first few days after 9/11. You want to see empty parks?
I was standing in front of Germany on 9/13 or 14 at noon, at the time designated as the national moment of silence for the victims of the attack. And I genuinely had a moment of silence, as there was no one anywhere near me. (True, there had been a tropical storm go through a few hours before, but this was hard to imagine.)
That week I dined at CRT twice as a walk-up - and this was back in the days of full CRT insanity, when breakfast was the only character meal.