[4] On the morning of 9 August 1945, the 16-year-old Taniguchi was approximately 1,800 metres (5,900 ft) north from the hypocenter, delivering mail on his bicycle without a shirt on due to the warm summer weather, when "Fat Man" exploded in the sky over Urakami.

The bomb's heat flash heavily injured Taniguchi with near instant burns resulting, but the blast that arrived afterward did not cause any severe injuries to him, as he clung to the ground while buildings were blown down around him.

By mid-September he was moved to a primary school clinic in Nagasaki to receive the first course of medical treatment from a University Hospital team.

[7] In November, Taniguchi was transferred to Omura Navy Hospital, where he spent the next 21 months lying on his stomach due to the severe third degree burns on his back.

"[8] The color photograph(s) of Sumiteru Taniguchi's red back are from motion picture film taken by (attributed to) Lieutenant Herbert Sussan.

[3] He returned to work back at the post office in Nagasaki shortly upon discharge despite needing to receive medical treatment and doctors advising him that he would not be able to.

[12] Taniguchi gave numerous interviews recounting his experiences and was featured in Steven Okazaki's 2007 documentary White Light/Black Rain: The Destruction of Hiroshima and Nagasaki.