In 2020, nuclear historian Alex Wellerstein published original research with the Bulletin, describing the challenges of tabulating the casualties of the bomb in #Hiroshima and #Nagasaki. Without accurate records of the population prior to the bombings, Allied forces and the Japanese government relied on proxy figures to come up with their estimates. Decades later, those estimates were revisited to account for information that was excluded at the time.
https://thebulletin.org/2020/08/counting-the-dead-at-hiroshima-and-nagasaki/