after the start of wwii, when belgium fell under nazi occupation, 13-year-old klieger helped found a zionist youth underground organization. members of his group passed messages between adult underground cells, helped obtain ration stamps, and smuggled belgian jews to switzerland. overall, klieger's cell successfully smuggled some 270 jews to this neutral country. however, when his own turn came to leave belgium in 1942, he was caught at the border by the germans.