Jan Zimmermann was seven years old when the Second World War began. His parents fled Przemyśl for a short time with him and his older sister Teodora.
After the city was occupied by the Wehrmacht at the end of June 1941, Jan Zimmermann was no longer allowed to attend school. His father’s factory was expropriated and the family had to move into a ghetto in 1942. In November 1942 Jan’s father Wilhelm Zimmermann was taken to Bełżec extermination camp and murdered. The Zimmermanns decided to escape the ghetto. Leon Hirsch, a friend of Jan’s mother Malwina, arranged a hiding place for them.
In the summer of 1943, Jan and Teodora Zimmermann escaped from the ghetto, followed by their mother. They were hidden by Stefania Podgórska in an attic, where ten other Jews were living. Stefania Podgórska and her younger sister provided the escapees with food. Jan Zimmermann had to share a cramped hiding place with 12 other people. Fearing discovery, they rarely left the attic until their liberation in July 1944. Malwina, Teodora, and Jan Zimmerman later emigrated via Germany to the United States.