I was sitting at my desk at work, checking the web for computer viruses (the Beeb and Yahoo News always published news first - and that was a time when people kept sending out those nasty viruses). Anyway, I open up Yahoo News and find a photo of one of the twin towers with a hole punched in the side, some text about a plane hitting it. I went, 'crap, how could a Cesna punch a whole that big in a building?' thinking, heck, only light planes could possibly buzz around inside the city. The rest is sort of a blur, as people had heard about it on radios, or something, and then it all went to hell when the first tower continued to smoke and then the second plane struck. After it came out the Pentagon got attacked as well, I thought, geez, World War III has begun!
Somewhere during the whole mess, I emailed a friend who worked at one of the towers. No response, but way later that day I managed to fortunately talk to her on the phone. She'd been running late for work, and had the TV on. When she saw the first tower get hit, she wisely did not go into work (second tower). [The next day her email bounced back with the prophetic "fatal error" message from the server, which I suppose, bit the dust along with the towers.]
I'm lucky enough not to have known anybody who died in the towers, althought some family members did - a coworker was in one of the planes, and another friend was trapped up on a high floor, on his cellphone, making his last calls. Chilling :(
I also remember that spagetti was on sale that day. Somwhere in the attic is a box full of newspapers from that first week. I'd collected all the local NYC papers, knowing I wouldn't read them till who knows when (ditto for the videotapes I made of CNN and CBS for a few days).