Doctors who had participated in the "Aktion T4" mass killings toured several concentration camps to select ill inmates to be transported to euthanasia centers; they visited Flossenbürg in March 1942. Thousands of prisoners who were worn out by forced labor were sent to death camps such as Majdanek and Auschwitz. One transport from Flossenbürg to Auschwitz arrived on 5 December 1943 with more than 250 of the 948 prisoners dead. By 18 February, only 393 survived. Women unable to work were often deported to Ravensbrück concentration camp.