At Princeton he was in the Navy V-12 program. He went on to be a Navy officer, serving internationally, with much sea duty, for a quarter-century. He then became a high-school teacher in San Diego County, Calif.
In 1951 he met Mitako Shinohara of Kitakyushu, Japan, and in 1954 they married. They were parents of a daughter and two sons.
Irwin died Feb. 25, 2019. He was 96.