I was at work (instead of college, as the academic year hadn't yet begun). At the time I had a part-time job working in a supermarket. I was working on the checkouts working a 1300-1800 shift when the first plane hit. During that hour, the credit card payments systems continually failed to authorise certain card transactions. Allegedly this was due to some UK card issuers being unable to communicate with Morgan Stanley (not sure how correct that theory was). The first I heard about it was when one of my supervisors showed up with the device and carbon copy slips to perform manual card payments. She said it was caused by a plane crash in NYC. At the time I couldn't work out what she meant by that and carried on doing my job. A colleague ran back and forth taking card details to get authorisation codes by phone but the card issuer phone lines were busy. A few customers were frustrated by this but accepted that something was amiss with the World, despite not knowing exactly what was unfolding.
I was told to go have my 15 minute break and watched the TV in the staff canteen in disbelief as the 2nd plane hit. As soon as my shift was over I went home and continued to watch the live news coverage. I had satellite TV, so we switched between the US news channels. I had no work the following day so continued watching the news. A couple of friends called by and I remember one, who was a big fan on Frasier, getting visibly upset that David Angell had died on AA Flight 11.
I had been gone from the cult for almost 2 years at this point but had not yet been officially DA'd. I never thought at the time that it could be the start of the GT/Armargeddon - for me that thinking occured when US Forces attacked Afghanistan.
For the most part I felt awful about what had happened, but as the attacks targeted centres of capitalism and politics, it was easy to feel disassociated when you live thousands of miles away in a sleepy little back-water town (which not even the Nazis bothered bombing during WWII). It wasn't until 7/7 happened that I felt the greatest degree of empathy, as having friends and family members in London whose lives were impacted by the bombings, the terror threat suddenly became a great deal more real.
There have been some very eye-opening documentaries aired on UK TV about the events of 9/11 in recent years as more eyewitness accounts and private film recordings have been collated. Since becoming a mother I can no longer watch them without getting very upset.