I was 20 and I came home from town that afternoon (the attacks started around 2pm our time) and came into the house to see my brother surfing the web on the PC in the dining room (I didn't use the internet then and didn't really know what it was and just wasn't interested). Our parents and sister were out somewhere. I went into the living room, switched on the TV and there it was on every channel (Britain only had five TV channels back then) - planes had crashed into the World Trade Center etc. I couldn't believe what I was seeing. Every channel - BBC 1, BBC 2, ITV, Channel 4, Channel 5 - was showing live footage of smoke billowing from the Twin Towers. I then realised planes has flown into them. I shouted through to my brother and told him some planes had flown into the World Trade Center, expecting him to come and watch, but he didn't seem interested. He sort of just ignored me and carried on websurfing. I still don't know to this day whether or not he already knew about it after finding out online. So I just stood there in the living room watching in disbelief. Then I saw one of the towers collapse live on TV. Not long afterwards I saw, through the living room window, a car pull up on the driveway containing my parents and sister. I ran to the door and shouted: "Have you seen what's happening?!" My dad shouted: "Just let us get out of the car first!" Then I can't remember anything until that night when we were all watching a news special about it, and my mum turned to me and said something like: "When you shouted to us as we were getting out of the car we didn't realise just how serious it was!"
It's crazy to think it was 20 years ago - half my current lifespan. It only seems like a few weeks ago.