Wiesenthal escaped himself in 1943, working briefly for the Polish Underground. He was recaptured in 1944 and sent to the Gross-Rosen camp, then forced to participate in two separate death marches: first to Chemnitz, then to Mauthausen.
It was at Mauthausen that Wiesenthal finally greeted liberation. He had been hospitalized for three months due to an amputated toe and case of gangrene caused by the death marches. When American troops entered the camp, the 6-foot-tall Wiesenthal weighed 99 pounds.