the Schmelt labor camps became part of Auschwitz and Gross-Rosen. (Oskar Schindler's camp was originally under Organization Schmelt.) In 1941, Gertner was allowed to return home. She was employed in various local workshops and offices run by Moses Merin. She and Bernhard Holtz were married in the Sosnowiec Ghetto of Środula on 22 May 1943. They lived in the Będzin Ghetto neighbourhood of Kamionka until sometime after 16 July 1943 (the date of Gertner's last known letter) and were probably deported to Auschwitz with the remaining Jews of Sosnowiec and Będzin in early August 1943. At Auschwitz At Auschwitz, Gertner worked in the warehouses at first, sorting the possessions of Jews who had been gassed. She became friendly with Roza Robota, who was active in the underground resistance. Gertner was then assigned to the office of the munitions factory, where she and Roza became part of a conspiracy to smuggle gunpowder to the Sonderkommando, who were building bombs and planning an escape. Gertner recruited other women to join the conspiracy, and passed the stolen gunpowder to Roza. On 7 October 1944 the Sonderkommando blew up Crematorium IV, but the revolt was quickly quelled by the armed SS guards. A lengthy investigation led the Nazis back to Gertner and Roza, and then to Estusia Wajcblum and Regina Safirsztajn, who were also implicated in the conspiracy. They were interrogated and tortured for weeks. On 5 January 1945 the four women were publicly hanged in Auschwitz. Other sources give 6 January as the date of the execution. This was the last public hanging at Auschwitz: two weeks later, the camp was evacuated. Legacy Gertner left no known survivors or family, but her 28 letters to a camp friend, Sala Kirschner (née Garncarz), also from the Sosnowiec Ghetto, are among the 350 wartime letters that are in the permanent Sala Garncarz Kirschner Collection of the Dorot Jewish Division of the New York Public Library. The heroism of the four women was recognized in 1991 with the dedication of a memorial at Yad Vashem. This is the text of Gertner's last known letter: Kamionka 15 July 1943 Dearest Sarenka, Suddenly I’m here at the post office. The mail is going out today and how could I not write to my Sarenka? Just now, my husband, little Bernhard was here. He looks good and feels well. I’m curious about how you are, how your health is.