I live in permanent fear of something happening to the people I love. In one sense, it's a good thing - I know that my relationships with those people are stable enough that the only thing that could take them away from me would be some sort of third party intervention. In another sense, it's a total raving paranoia that I could do with getting rid of. Unsurprisingly, the news report that upset me the most wasn't anything to do with dramatic photos of people dying - it was "Phone home, you're going to die". Probably because I'm always afraid of getting a phone call like that.
The scale of the tragedy is beyond my comprehension. katyha said some interesting things about relative numbers of deaths. I suppose I agree with adjectivemarcus's comments on it. It was the total unpredictability - the sheer randomness of the attack that made it so horrifying for me. The first couple of hours after it happened, no one knew what was going to happen next. There were rumours of planes hijacked at Heathrow. I live something like 8 miles away, right under the flight path. We don't really have skyscrapers in London to the same extent as many American cities, but there is Centre Point - if that came down while Richard was at work, he'd go with it. Sheer panic and madness. And meanwhile, a few people who hadn't seen the news yet going blissfully on with their lives.
And once again, I get a song stuck in my head.