I very much remember what was happening to me on 9/11. I was at Strong Memorial Hospital with my mom for a follow-up appointment after her liver transplant in 2001. We were in the waiting room and saw early coverage of the event in NYC but the assumption at that point was that it was a commuter plane so we did not think much about it. When we did go upstairs to the doctor's office, I started fiddling with the television to get it off the silly radio station it was playing and managed to get our local ABC station. People in the office, as well as doctors and staff, started sticking their heads into the waiting room and watching the coverage. We were all stunned when Peter Jennings asked "the whole building collapsed?" The reaction of many of the people in the waiting room seemed more numb than anything. One woman kept right on knitting, which I thought was surreal at the time.
After the first tower collapsed, most people started getting on the hospital phones and that led to an announcement on the PA system telling people to get off the phones because nobody could make or receive calls. On the way out of the hospital, most people had televisions, radios, or cell phones trying to figure out what was happening. We heard Dan Rather on the radio tell us in a resigned tone the second tower had collapsed while we in the parking garage on the way out.
Most of the rest of the day was spent watching television. Most cable networks signed off and started relaying their parent company's network broadcasts. The shopping channels shut down. For the remainder of the week, most networks seemed to be staying with the story 24/7.
I remember later that day when I was out on my daily walk that everything had effectively changed that day. It would be, in a sense, the first war I would be living through (I was too young to really comprehend Vietnam).
Of course, the thing that would later upset me is the unity we had in the country squandered by an administration that would seek to use the event for political purposes, and that a neocon thought experiment would get us into a quagmire in Iraq, a country that had nothing to do with 9/11 and a limited, at best, involvement in the greater war on terror.
Today will be a largely normal day for most Americans. Although events are taking place around the country, I think most Americans will be dwelling on 9/11 primarily through the saturation media coverage, documentaries and dramas that the television networks are dropping on us.