Sumiteru Taniguchi, who devoted his life to seeking to abolish nuclear weapons after he was burned severely in the 1945 atomic bomb attack on his hometown of Nagasaki, died Wednesday of cancer. He was 88.

Taniguchi died at a hospital in Nagasaki of cancer of the duodenal papilla, the point where the pancreatic and bile ducts meet, according to the Japan Confederation of A— and H—Bomb Sufferers Organizations.

Taniguchi was 16 and was on the job delivering mail on Aug. 9, 1945, when a U.S. atomic bomb was dropped on the city. The blast 1.8 kilometers (1.1 miles) away threw him from his bicycle, almost killing him. The Nagasaki attack killed more than 70,000 people. The bombing of Hiroshima three days earlier killed an estimated 140,000.

In an interview with The Associated Press two years ago, Taniguchi peeled his undershirt off to show his scars, to describe his painful past and tell the world the tragedy should never be repeated.

In his video message in July, Taniguchi welcomed the U.N. nuclear weapons prohibition treaty, but expressed concerns about the declining population of the survivors, known in Japan as hibakusha. “I wonder what the world will be like when it loses the last atomic bombing survivor.”