Adolph Hitler and the Nazi regime set up networks of concentration camps before and during World War II to carry out a plan of genocide. Hitler’s “final solution” called for the eradication of Jewish people and other “undesirables,” including homosexuals, gypsies and people with disabilities. The children pictured here were held at the Auschwitz concentration camp in Nazi-occupied Poland.

Survivors at the Wobbelin concentration camp in northern Germany were found by the U.S. Ninth Army in May 1945. Here, one man breaks out in tears when he finds he is not leaving with the first group to be taken to the hospital.

Survivors at Buchenwald concentration camp are shown in their barracks after liberation by the Allies in April 1945. The camp was located in a wooded area in Ettersberg, Germany, just east of Weimar. Elie Wiesel, the Nobel Prize winning author of Night, is on the second bunk from the bottom, seventh from the left.

Fifteen-year-old Ivan Dudnik was brought to Auschwitz from his home in the Oryol region of Russia by the Nazis. While being rescued after the liberation of Auschwitz, he had reportedly gone insane after witnessing mass horrors and tragedies at the camp.

Allied troops are shown in May 1945 discovering Holocaust victims in a railroad car that did not arrive at its final destination. It was believed this car was on a journey to the Wobbelin concentration camp near Ludwigslust, Germany where many of the prisoners died along the way.

A total of 6 million lives were lost as a result of the Holocaust. Here, a pile of human bones and skulls is seen in 1944 at the Majdanek concentration camp in the outskirts of Lublin, Poland. Majdanek was the second largest death camp in Nazi-occupied Poland after Auschwitz.

A body is seen in a crematory oven in the Buchenwald concentration camp near Weimar, Germany in April 1945. This camp not only imprisoned Jews, it also included Jehovah’s Witnesses, gypsies, German military deserters, prisoners of war, and repeat criminals.

Auschwitz camp, as seen in April 2015. Nearly 1.3 million people were deported to the camp and more than 1.1 million perished. Although Auschwitz had the highest death rate, it also had the highest survival rate of all the killing centers.

Prosthetic legs and crutches are a part of a permanent exhibition in the Auschwitz Museum. On July 14, 1933, the Nazi government enforced the “Law for Prevention of Progeny with Hereditary Diseases” in their attempt to achieve a purer “master” race. This called for the sterilization of people with mental illness, deformities, and a variety of other disabilities. Hitler later took it to more extreme measures and between 1940 and 1941, 70,000 disabled Austrians and Germans were murdered. Some 275,000 disabled people were murdered by the end of the war.

A pile of footwear are also a part of the Auschwitz Museum.