Yehuda joined the movement when he was a teenager. In the summer of 1944 he and another three members of the movement, were sent to South Transylvania in order to try and open a new route for the tiyul. They were all captured and sent to the Nyiregyháza ghetto and later to Debrecen where they were imprisoned in the wagons of a train bound for Auschwitz. When the train arrived to Slovak territory, three of them, Tzvi Lipkovics, Hillel Hacohen and Yehuda Alpar, managed to jump off. Tzvi Lipkovics was killed by his chasers but his two friends managed to reach Prešov. They made contact with a Jewish doctor who obtained Slovak documents for them from the “Hashomer Hatzair” movement in Slovakia.
Hillel Hacohen remained in Slovakia and joined the Slovak revolt but Yehuda Alpar returned to Budapest and stayed in the family apartment on Népszínház Street in a Yellow Star House. Later he arrived at the
“Glass House” on 29, Vadász Street, from where he was liberated on 18.1.1945.
Yehuda made aliya and joined Kibbutz Givat Oz. Later he left the kibbutz and settled down in Australia.