Andrée Geulen was not Jewish, but because of her, 300-400 Jewish children were saved during the Nazi occupation of Belgium. For that she was honored in 1989 by Yad Vashem as a Righteous Among the Nations, as recognition given to non-Jews who risked their lives to save Jews from the Nazi genocide.

She was a young Belgian teacher at an all-girls boarding school in Brussels in the 1940s when her Jewish students were no longer showing up for school. She soon learned why: They and their families had been rounded up by the Gestapo and sent to a camp in Mechelen, northeast of Brussels — a way station on the road to Auschwitz.

She volunteered to help a clandestine group, the Committee for the Defense of Jews, that spirited Jewish children out of harm’s way, to convents, monasteries, boarding schools, farms and families around the country that were willing to hide them. She said in testimony after the war, “I had some addresses, and I saw it as a race between myself and the Gestapo, who would get to the family first.”

She died at 100, on May 31, in a Brussels nursing home, the last survivor of a cadre of women who, working for the committee, together rescued some 3,000 Jewish children. They could not tell the parents where their children were heading for fear of exposing the families or the institutions hiding them.

After the war, Ms. Geulen fetched many hidden children and reunited them with parents who had emerged from their own hiding or who had survived the camps. She found apartments for the families, solicited charities to pay for adequate furnishings and negotiated with manufacturers for mattresses, blankets and sheets to give to the families.

One of the children was Helene Weiss, then an 8-year-old whom Ms. Geulen took to a farm owned by a Catholic family. When Mrs. Weiss, now 89, a retired bookkeeper living in Baltimore, learned of Ms. Geulen’s address at an event for hidden children, she wrote her a letter of gratitude for risking her life. “I sent her pictures of my children and grandchildren,” Ms. Weiss recalled in a phone interview, “and said, ‘If it weren’t for you, they wouldn’t be here.’”