On 20 July 1944 an assassination attempt was made against Adolf Hitler. The dictator survived, but the leadership were badly unnerved: the régime had already prepared a list of several thousand names of political adversaries, many of them surviving former left wing politicians from the Weimar era, to be used in the event of an escalation in political tension on the home front. Lisa Ullrich's name was on it. She was one of approximately 5,000 people arrested overnight on 22/23 August 1944, and was returned to Ravensbrück. There she was deprived of the medical supplies necessary to treat her health problems. Within her "accommodation block" her fellow internees elected her as "block senior". Responding to an obvious and urgent need in a women's concentration camp, she organised a "Mother and child" facility, collecting a team of four fellow inmates, comprising two doctors from Germany and Czechoslovakia, a paediatrician from Czechoslovakia, and a baby nurse. At the time the camp contained an estimated 150 pregnant women, 100 mothers of infants, and 96 babies and infants. She later recalled the struggle to try and ensure that all the "kids" survived, although given the absence of basic necessities in the camp this proved "well nigh impossible".