Lonka Korzybrodska was born in 1917 in the town of Pruszków, near Warsaw. The influence her father Avraham, a teacher, exerted on the young people of the town is evidenced by the fact that most of his students joined pioneer youth movements. As a young girl, Korzybrodska, who studied in Polish schools, generally socialized with Poles. She was active in the Polish socialist youth movement and was far removed from the concerns of Jewish youth. In addition to Polish, Yiddish and Hebrew, which she heard at home, Lonka learned French and German at university and easily added English, Russian, and Ukrainian to her list of languages.

In due course Lonka was influenced by her brother David (1914–1997), a member of the central leadership of He-Haluz ha-Za’ir-Dror, placing herself at the movement’s disposal with the outbreak of World War II. Korzybrodska, who had blonde hair and noticeably Aryan features, endeared herself to everyone she met. Blessed with great courage, she was one of the first female liaisons of He-Haluz throughout occupied Poland during the war. She took on the Polish name Kristina Kosowska, her Polish appearance and knowledge of languages facilitating her contacts with Germans, Poles, Russians, and Ukrainians. As an emissary of the movement’s central office in Warsaw, Korzybrodska visited the major cities of the Generalgouvernement, Ostland, the Bialystok district, and other areas annexed by the Reich, often accompanying Izhak (Antek) Zuckerman (1915–1981), a leader of He-Haluz ha-Za’ir-Dror in Poland. In January 1942 she was among the first female liaisons to travel from Warsaw to Vilna to investigate reports of the massacre of Jews in Ponary. Korzybrodska relayed newspapers, identification papers, money, and instructions to chapters of the movement in various locations and transported documents of the Jewish Self-Help organization (Jüdische Soziale Selbsthilfe) from Cracow to the secret archives in the Warsaw Ghetto.

Zuckerman later said of her: “Lonka was truly born to serve as a liaison. She had all the natural attributes for it. … She knew how to hide her true identity and a lot of her work was conducted via Germans. She developed contacts with soldiers, officers, railway workers, who never knew what they were transporting and what they were doing when they delivered her suitcases or performed other services for her.”

With the help of one of the members, Korzybrodska was preparing to travel to Switzerland as an emissary of the movement to alert the world and the Jewish community to the extermination of the Jews in Poland. The plan was cancelled at the last moment when the German officer involved in the operation backed out for fear of being discovered by the Warsaw airport authorities.

In January 1942 Korzybrodska smuggled Shahariyyah, the baby daughter of Yitzhak Engelman (of Dror), from the Vilna Ghetto to Grodno. There she stayed with Bela Hazan, another Dror liaison who lived under an assumed identity as a Polish woman in a rented room on the Aryan side of the city. The women transported the baby to Bialystok and turned her over to her father, who reached Bialystok with a group smuggled from Vilna. While in Bialystok, Korzybrodska and Hazan were sent by the movement to the surrounding towns to recruit participants for a meeting that took place in Bialystok.

Korzybrodska continued her missions for the movement until her capture in June 1942 at the border crossing at Malkinia, between the Bialystok district and the Generalgouvernement. She was interrogated as a Polish woman and held in the Pawiak prison in Warsaw. Since no one knew the reason for her disappearance, Hazan was sent to look for her and was captured at the same border crossing and also sent to Pawiak, where she learned that Korzybrodska was likewise a prisoner.

In her testimony years later, Hazan recalled her meeting with Korzybrodska in the cell where she was being held at Pawiak prison: “I had difficulty recognizing her. … She was all skin and bones, her face was pale. … Her health was not good, and the physical hardships made things worse for her. …”

Korzybrodska and Hazan conducted themselves strictly as Poles and tried to become friendly with the other women prisoners so as not to arouse suspicion. Korzybrodska spoke often to Hazan of her parents who were imprisoned in the Warsaw Ghetto and had no idea that their daughter was being held in the Pawiak. Since the prison yard faced a street where several He-Haluz activists lived, Korzybrodska threw notes into the street on a number of occasions in the hope that they would reach her comrades. Zuckerman later related that he did receive one note from Korzybrodska after it was discovered by a child from the orphanage of Janusz Korczak.

In November 1942, fifty-three female prisoners were transported to Auschwitz from Pawiak prison, among them Korzybrodska and Hazan. Both were held at Birkenau and assigned to the same group for forced labor in the fields. One day they spoke in German to their supervisor, who marveled at their command of the language, given that they were Poles. They responded that they had studied in gymnasium and were educated professionals. Korzybrodska stated that she knew several languages and was sent to work as an interpreter at the camp office.

At Birkenau, Korzybrodska and Hazan contracted typhus. Hazan recovered, while Korzybrodska’s condition worsened and she came down with mumps and dysentery as well. Hazan cared for her devotedly and did everything within her power to save her. But on March 18, 1943, at the age of twenty-six, Korzybrodska passed away in her friend’s arms.

Korzybrodska’s entire family perished in the Holocaust, with the exception of her brother David Brodsky, who left occupied Poland to Lithuania and later immigrated to the United States. He joined the American Army and in 1946 immigrated to Israel and settled in Jerusalem.