But Petty Officer Stahlschmidt, nicknamed the “Little Frenchman” by the French dock workers who knew him, chose to disobey the orders and instead exploded the bunker itself, killing as many as 50 Nazi soldiers.

Image A World War II hero: Henri Salmide in Bordeaux, France. Credit... Olivier Morin/Agence France-Presse — Getty Images, 1994

Wanted by both the Gestapo and the French authorities, Mr. Salmide hid with a French Resistance family in Bordeaux. After the war he married a French woman, Henriette Buisson, and was naturalized as Henri Salmide.

“I acted according to my Christian conscience,” Mr. Salmide told Reuters in an interview in 1997. “I could not accept that the port of Bordeaux be wantonly destroyed when the war was clearly lost.”

Heinz Stahlschmidt was born on Nov. 13, 1919, to a German plumber and his wife in the western German city of Dortmund. After World War II, he was considered by many Germans to have been a traitor. He worked as a firefighter in Bordeaux but struggled to win recognition in France as well.

“No one wanted to admit that he had done it,” Mrs. Salmide said in a telephone interview. “If he had been French, it would have been easier for him.” She is his only immediate survivor.