It was a Tuesday, I remember clearly (at least in the States).
I was 20 and lived in pretty much a party house (that I’d only been living in for about a month) and we all slept in due to the previous night’s drinking session. Some missed their college classes, although I was just working full time at that point. My dad was coming over to help with a project to fix up my closet and some shelving. A friend attending RIT called and told us to wake the fark up and turn on the TV. I think it was too late to even see the towers collapse, or maybe saw the 2nd one. I believe one of the other planes went down after that as well (maybe the Pennsylvania one? not sure). I remember my dad saying: “Someone’s going to pay for this, just watch.”
Anyway, work called me and asked if I wanted to stay home because of the day’s events. Didn’t need to.
Later that night we sat on the front porch and it was eerily quiet. Seemed really odd.
Looking at footage later, it does seem pretty gruesome, especially people jumping from buildings and such.