Matisse remained for the most part isolated in southern France throughout the war but his family was intimately involved with the French resistance. His son Pierre, the art dealer in New York, helped the Jewish and anti-Nazi French artists he represented to escape occupied France and enter the United States. In 1942, he held an exhibition in New York, "Artists in Exile," which was to become legendary. Matisse's estranged wife, Amélie, was a typist for the French Underground and jailed for six months. Matisse was shocked when he heard that his daughter Marguerite, who had been active in the Résistance during the war, was tortured (almost to death) by the Gestapo in a Rennes prison and sentenced to the Ravensbrück concentration camp in Germany. Marguerite managed to escape from the train to Ravensbrück, which was halted during an Allied air raid; she survived in the woods in the chaos of the closing days of the war, until rescued by fellow resisters. Matisse's student Rudolf Levy was killed in the Auschwitz concentration camp in 1944.