In my entry of 01 October, I talked about how strange it felt to know so many people who’d had near escapes from the WTC disaster, or who knew people who’d been killed, when no one I knew personally had died.

It turns out I’m not alone. According to David Plotz’s piece, “Why Didn’t I Know Someone Who Died? Life’s Odds and Sept. 11”, the entire staff of Slate found themselves in the same position. This prompted Plotz to look into statistical analyses of the odds that any one person would know a victim of the WTC disaster.

If the calculations are correct, around 1.1 million people were personally acquainted with one or more of the dead. “Fewer than one American in 200 is likely to know one of the 6,000,” he says — a useful way to think about it, though neither the dead nor the mourners can be assumed to be Americans. But if they were, then more than 80% of the people in America would know someone who knew someone: “We are all mourners at the second degree.”