I had just come back from a meeting at C5F about something that no longer mattered when a few minutes later I noticed people hanging around the TV that was always on.
It got my attention just a few minutes after the first plane hit. It was a long couple of days that changed everything...and not for the better for anyone.
I've made it my custom for the last decade or so, on this particular anniversary, to go visit a maternity ward...........
One thing people forget: around that time you had several incidents of planes crashing into buildings. Iirc, 1 or 2 of students crashing after flying closer than their experience possibly warranted, 1 guy showing off, and one deliberate crash to be part of an "art installation" project. So like the local talk show host, I thought "another idiot". After the 2nd plane was reported, I thought, "Someone sent in the first string".
Somewhat worried the rest of the day we'd get hit with a truly serious attack against the grid or fuel distribution.