It's one of those world-changing events that you remember where you were when it happened.
I was in the US at the time. A friend and I were away on holiday and had been camping in Canyonlands for a few days, a beautiful, isolated place in Utah. We were just on our way out to the next stop and had stopped off at the campsite shop for a coffee and muffin. People were standing around staring at the TV screen - obviously in shock, saying "they're both gone" - the towers that is. By this time both towers had already collapsed as we were a couple of hours behind. They were just repeating over and over again the only footage they had. Repeating the little news they had, on every channel as it was all they could do.
We watched the horror as it unfolded throughout the day. Everywhere we stopped people were watching the news, glued to the screen for the latest news as the realisation that this was a terrorist attack. The pictures of the planes crashing into the buildings repeated over and over again. The third plane striking the Pentagon, Flight 93 coming down in the countryside and not hitting it's intended target. Slowly bulletins being added to as more news and pictures came in but very little sense being made of it all.
We both had friends and colleagues who worked in one of the nearby office buildings, so there was concerned for their safety, until we finally heard they were OK. My parents had flown in to the country the day before, so I knew they were safe but it was good to talk to them anyway. It was all shocking and very emotional. Watching people desperately searching for their loved ones. Joy and tears when they were found, grief and desperation when they weren't.
Watching the documentaries and reruns this week - it's still terrible to be reminded of the loss of life and tragedy of the day. For the 2,749 lives that were lost. Their families, friends and colleagues whose lives were changed forever.