This actually jives with my personal experience living in NYC.
New Yorkers have a reputation for being stone cold with strangers, but the truth is that anytime somebody approaches you out of the blue, there's an assumption that they're about to ask for money or try to get in your pants. Once you demonstrate you're not looking for either (or, if the second I suppose, that you're at least smooth enough for it not to be immediately evident), people are generally really kind. With some exceptions, I've usually found that the coldest looking person will stop to give a lost tourist directions if it's clear they're in need.
I went to Stuyvesant high school, and graduated in 2000. Stuy was a few blocks from the trade center, and I had friends who were still in high school that day. I knew people who saw the first plane fly in.
Was a bad day. There was a part of me that felt a weird guilt for not being there. Like, as a lifelong New Yorker, the trauma was part of my birthright somehow, and being away for school made me feel strangely removed when I felt like I should be feeling it in my bones.
My mother had PTSD for a good while afterward, and she lived way uptown from the trade center.