At 8:16 on the morning of August 6th, 1945, the Enola Gay, a B-52 super fortress, changed the course of history when it dropped the world’s first atomic bomb on Hiroshima.

The bombing which killed at least 100,000 people, caused the plane’s co-pilot to write the phrase, “My God what have we done.”

Captain Robert Lewis chronicled every spectacular and awful moment of that flight. There are 11 pages of notes and they’re considered among the the most important documents of the 20th century.

The Enola Gay Logbook has been held in a private collection. Heritage Auctions plans to sell it at it’s Historical Platinum Session Signature Auction on July 16th.