As a teenager during WWII, Frank Blaichman fled into the forests of eastern Poland to avoid a roundup of fellow Jews by occupying Germans. He soon became a leader of a band of partisans trying to disrupt the Nazis from inside the country. He died on Dec. 27 at his home in Manhattan at the age of 96.

Mr. Blaichman settled in the U.S. after the war, where he was active in promoting the legacy of the partisans, hoping to counter the misperception that all Jews went passively to their fate and that none had fought back against the Nazis. He spent the war disrupting German supply lines and communications, and ferreting out Poles who were collaborating with the Nazis.

He told his story in a 2009 book, Rather Die Fighting: A Memoir of World War II, as well as in an oral history recorded for the U.S. Holocaust Memorial Museum and in several documentaries.