Vienna. Abraham Wald is a young Austrian statistician. He comes from an Orthodox Jewish family. With the Anschluss (annexation of Austria by Nazi Germany), his world collapses. That same day, March 11th, his academic tutor and benefactor, Karl Schlesinger, commits suicide. Abraham Wald will clandestinely cross the border into Romania and leave for America. His parents, grandparents, and five brothers and sisters will all remain in Austria, and all but one, his brother Hermann, will lose their lives in the Holocaust. In the United States, he begins his career in Colorado Springs, but is quickly noticed by those in high places, and after a few months (fall 1938) he receives a research contract at Columbia University in New York. He will help the Air Force (USAF) use conditional probability and Bayes’ Theorem to calculate where to strengthen airplanes (the simple answer is near the engines). The work is not simple because it must necessarily start from a good model (a priori probability), which is developed by interviewing expert aviators and engineers and also by conducting tests. This technique will also be used for other aircraft, such as the B-52. Its algorithm will not be published until the 1980s.
