This past week was the 75th anniversary of the Hiroshima and Nagasaki bombings. I found this article "Hiroshima" on the New Yorker that goes into detail about the actual experiences of survivors in the days and weeks afterwards and it's sobering. Not just because of single event, as they're all sobering, but the sheer volume.
It's a long read (~100 pages) and well worth your time. What's more is that it's not based on long-ago recollections. This article was originally published in August 1946.