When the German Wehrmacht attacked Warsaw in September 1939, the activist and social worker Eugenia Wąsowska was working for the Polish Red Cross. She organized soup kitchens for needy Warsaw residents and cared for wounded Polish soldiers. She also actively supported Jews who were then persecuted by the occupiers. In 1942 Wąsowska made her Warsaw apartment available for the underground organization Żegota, which then regularly held secret meetings there. The apartment was also used by Jewish fighters who hid money, weapons, and secret documents there. Starting in 1943, Wąsowska hid Jewish members of Żegota in the apartment, such as Leon Feiner and Adolf Berman. The resistance fighter Ignacy Samsonowicz also found long-term refuge at Wąsowska’s after escaping from the ghetto. Wąsowska and Samsonowicz then fell in love. After liberation, Samsonowicz changed his name to Leszczyński and the two got married.
In 1985 Eugenia Wąsowska-Leszczyńska was honored by the Israeli Holocaust memorial Yad Vashem as Righteous Among the Nations.