New York besieged: 11 September and after.

E pidemiologists all over the world have been good enough to express their concerns and worries about how we, and other friends and colleagues in New York, fared in the terror provoked on 11 September. This annotation responds to the editors' invitation that we convey something from our vantage point. We welcomed their interest. The experience is, so far, unique in history. Our account is personal, that of four individuals, all related (Sally married to Ezra, and Ezra born to Mervyn and Zena). We share the same house. Also, atypically for any institution, all are of the Department of Epidemiology in the Mailman School of Public Health of Columbia University. The themes we emphasise are common to many others among us in New York City. On the day of 11 September and after, much of what we saw and heard was televised, a source open to everyone else here and elsewhere. In some degree, then, much of the world was exposed to the New York experience. But in the Department of Epidemiology (the School and the Medical Center are on the north west outskirts of Manhattan) we were not only in propinquity to the events, we looked directly upon them from the south facing windows of the 18th floor of our own dwarfed tower. On the day of 11 September, only Sally and Ezra were in the city. Zena and Mervyn were in South Africa. We tell the story as it unfolded in both situations. In New York, immediately the first plane hit the South Tower of the World Trade Center, many of us, alerted to what seemed a tragic accident, went to our south looking windows. From there, horrified, we watched a second plane enter our view, veer toward and then disappear into the North Tower, becoming instantly enveloped, together with the upper levels of the tower, in a vast sheet of flame. At once, all understood the " accident " to be what it was—unimaginable evil. It was clear that twenty to thirty thousand people working in the Towers every day could be at risk, not counting even larger numbers visiting on business. In shock or fright, first thoughts for many of us revolved around the fate of the friends or relatives whose work brought them there, and that of the children we knew to be in schools nearby. In the Medical Center, Ezra and many senior faculty …