On February 7, 1985, a group of about 30 Josef Mengele survivors told their survival stories to an audience at Jerusalem's Yad Vashem Holocaust Memorial. One of the survivors, Vera Alexander, described how Mengele impregnated a girl with the sperm of another twin. But when he saw that there was only one baby and not twins, he tore the baby out of the mother's uterus and threw it into an oven. This story, along with many others, can be read here: Survivors