Is there anyone I know trapped in the wreckage?

It's the question that everyone has been asking themselves after the events of this week. And for the writer and columnist Philip Hensher, it led to a powerful exploration of his own feelings of shock and outrage

The sensation is of grief, overpowering but untethered. Over and over again, on the little screen, you watched the same scene, repeated many times. The first time, it was a spectacular scene from a movie. Even while the President of the Free World was failing to fulfil the obligations of his nation's popcorn fictions, and, instead, running for the bunker, one's mind was protecting oneself by insisting that, yes, this was just like a movie, expensive, spectacular and ultimately harmless.

And the clip was rewound, and played again and again, and that deplorable, instant reaction began to fade, and it began to look like two of the biggest buildings in the world being brutally destroyed in the space of an hour. It went on, and new views, new film started to be added to the mind's repertoire of cruelty, and it was not long before there was something there, an awareness from which nothing could shield the mind. What had, not long before, seemed spectacular now looked like what it was – the sight of people in their hundreds and thousands, dying simultaneously, dying in formation, dying in their thousands.

And against that, against the unspecific, unnameable grief, there is no protection, and none that one would wish for.

Now, there is nothing to do but wait for a name. I don't know what that name will be, but I know that when it comes, it will leap from a page filled with other names. Like everyone else, I spent Tuesday and Wednesday trying to phone everyone I could think of in New York, or everyone who could have had a reason to be there. Some of those phone calls, for other people, would have ended in a different way. I went on calling until I had an answer – four or five times. Other people are still calling, not knowing how to stop; there will be many who, now, are desperately entertaining the last shreds of doubt. But for the moment, the people that I thought of and called are secure and alive.

But it isn't yet over, and beyond the people you know and think about regularly, there are dozens, perhaps hundreds more, and the terror is that one day soon, a newspaper will contain a name you remember, and never thought of. Over the years, I've probably met hundreds of New Yorkers. Dozens of people I was at university with went into the City, and disappeared from my life into a busy existence of transatlantic crossing and arbitrage. God knows how many people, somehow, briefly touch your life with a short friendship, a pleasant conversation, a party encounter, or something even more casual. The pain of this is in the teeth-clenching certitude that so many of these people, so many friends of friends, went in that direction, and so many had some kind of reason to be in the World Trade Centre on 11 September, and there is no way of knowing who was there, and if the blow falls, it may be in months or even years.

There is no comparing this tense waiting for grief, with the loss of a close friend, a partner or a parent, but it is just as real, and, in its own way, it will be terrible. And I want it to be. I want people to understand what this kind of act means in human terms, and although for the majority of us, we will be lucky enough not to have a direct, personal bereavement, this does feel close enough to home to force an understanding of what war and murder means. And that is true whether or not we are going to have to cross out a name in our address books; it feels terribly close to home, and not just because we were shown the sight of mass murder, over and over again, like the "money shot" of this summer's blockbuster.

Grief, now, is inescapable. It is too much to hope, though, that we might somehow stop thinking that a tenuous personal link is the only reliable basis for high personal outrage, the only means by which we will allow ourselves to feel wounded. All over the world, murder on a gigantic scale is ordinary, but our feelings of grief and rage are generalised, if they have any substance at all. The sensation of being exposed to wickedness on an incomparable scale is unavoidable, because we probably knew someone who was there, or nearly there; it is, most of all, the feeling that we have probably been there or could have been there ourselves.

We have not been to Rwanda, or Chatila, or Afghanistan lately; we don't know the people who died there, and we don't know anyone who knows anyone who died there. We try to care, but our feelings are not ones of overpowering, tensely waiting grief. At this moment, our belief is probably not that our humanity has limits circumscribed by the narrow borders of our acquaintance and the probable edges of our experience, but a conviction that we could not care more, and there is no limit to our sympathy and humanitarian love.

There is nothing to be done; there is no way of transforming our concern for people we never knew into something like grief for the people whom we might well have known. At the moment, it all seems to be over, but it is not; there is nothing to do but wait, and hope one is waiting for nothing. And when we can wait for news in this spirit when Orissa is flooded, when millions in Afghanistan are starving to death, when hundreds of thousands are murdered in Rwanda, then we will have earned the right to call ourselves human beings.