On this day in 1945, Allied troops arrived at the Mauthausen concentration camp. On the following day, the third United States Army liberated around 40,000 prisoners. Prior to the Allies’ arrival, SS officers began destroying evidence of the crimes they committed and fled the camp. Prisoners formed their own committees which worked to preserve evidence against the SS in their commitment to create a ‘world of free men’.Along with the army, a war crimes investigating team also arrived at Mauthausen. Hundreds of people were killed days before liberation, and thousands more people were so ill that their lives could not be saved even after the Allies arrived. With the help of the prisoners’ committee, the investigating team captured surviving key documents, creating the basis to prosecute war crimes. While other prisoners were able to return home via convoys organized by the Allies, countless more remained behind in displaced persons’ camps who were unable or did not wish to return home. Many of them spent years in the camps waiting for contacts from people they knew or for a safe place to go.