Josef Indig was a member of a Zionist youth organization in Croatia. In 1941 he took on the care of a group of refugee children on behalf of the Youth Aliyah aid organization. The 42 children from Germany and Austria were on their way to British Mandatory Palestine. They had been stranded in Zagreb because they did not have permission to enter the territory.
When German troops occupied Yugoslavia in April 1941, Josef Indig took the children to Italian-occupied Slovenia. They stayed in a hunting lodge in Lesno Brdo for a year. Due to incessant partisan fighting, the group then fled to Nonantola in Italy. The aid organization Delasem rented a villa for them there. The German invasion of Italy in September 1943 placed the children in danger once again. Indig started by arranging hiding places nearby. He and Goffredo Pacifici planned an escape to Switzerland. In October 1943, the group managed to cross the border. They were placed first in a refugee camp and then later in a home in Bex in the Rhône Valley.
In 1945 Josef Indig finally reached Palestine, along with numerous children from the group. He adopted the name of Ithai there.