Sounds like you're referring to "Hiroshima", published as the entire editorial content of an issue of the New Yorker shortly after the war, later published as a

Sounds like you're referring to "Hiroshima", published as the entire editorial content of an issue of the New Yorker shortly after the war, later published as a book of the same title, and IMHO one of the most important magazine articles ever written. (For instance, here's an entire web site about that article: http://www.herseyhiroshima.com/index.php http://www.herseyhiroshima.com/index.php)