In November 1939 he was arrested by German Nazis during their purge of Kraków 's Polish intellectuals ( Sonderaktion Krakau ) . Until February 1940 he was a prisoner in the Sachsenhausen concentration camp . Upon his subsequent release , he joined the Polish Underground State . He became a member of the Committee of Three , which took care of aid to the persecuted families of people related to the university ; he was also active in the underground education
Sonderaktion Krakau
Sonderaktion Krakau
Stanisław Kutrzeba