Two months after an atomic bomb destroyed Hiroshima on Aug. 6, 1945, the United States Strategic Bombing Survey commissioned by President Harry S. Truman began to study the extensive structural damage done to the city, from the reinforced-concrete buildings at its center to the traditional wooden ones on its outskirts. Truman’s goal was to collect information that would help U.S. architects and civil engineers design structures able to withstand a nuclear attack. The secretive report included 700 images of Hiroshima.

This article is a series of selected photos from the study.