Here, Hungarian Jews and Russian soldiers, mostly, were kept in the open, all year round. Mauthhausen was classified a so-called "category three camp". This was the fiercest category, and for the prisoners it meant "Ruckkehr unerwunscht" (return not desired) and "Vernichtung durch arbeit" (extermination by work).
In the summer, the prisoners were woken up at 4:45 am., in the winter they were awoken at 5:15 am., the working day ended at 7:00 pm. This included two roll calls and the distribution of food rations. All the activity revolved around the Wiener Graben and the underground tunneling at the sub-camps of Gusen (I,II, and II), Melk, and Ebensee. In the Wiener Graben the prisoners were divided into two groups; one group that hacked into the granite and the other group that carried the slabs up the 186 steep steps to the top of the quarry.
An eyewitness report from Olga Wormser perhaps can give a hint of the life in the quarries. "87 Dutch Jews were sent to the quarries separated from all the other prisoners. There they encountered the effeminate SS men known as "Hans" and "the blonde Damsel". These two with pick handles in hand flailed into this pathetic group who were digging into the mountainside. By 11:30 am., 47 of the 87 lay dead on the ground. They were butchered, one after another, before the eyes of fellow prisoners, helpless to do anything. That afternoon, 4 more prisoners were killed. They were taken to the cliff top and told to fight. When 2 dropped to the rocks below, the victors would go free. Two dropped, but the victors were immediately pushed to join them."
Another killing method, favored by the SS during the winter months, was to gather a group of prisoners in the garage yard and order them to undress. A guard would then spray water on the group which was then left to freeze to death. This was quite effective in a region where the winter temperatures were a high of -10 degrees celcius (14 degrees fahrenheit).
If possible, the Gusen complex was considered even a worse fate than Mauthausen. Here the death toll was so high that each barrack was divided in an "A" and "B" ("Stube A, Stube B") part. The sick, wounded, or those too weak to work were thrown into Stube B. Here, covered in their own excrement and those of others, they lay upon the ground or on each other, wherever they'd been flung, and left to die. No food or water reached Stube B.
In the Ebensee and Melk sub-camps the situation was just as horrible. In mid April of 1945 when the whole Mauthausen complex was in total chaos due to the mass evacuation from other camps, cases of cannibalism were reported.
On May 5, 1945, units of the American 11th Armored Division liberated the main camp at Mauthausen. 15,000 bodies were buried in mass graves. Due to diseases and starvation, 3,000 prisoners died in the weeks following the liberation.
From 1937 to 1945, more than 10,000 SS guards served in the Mauthausen complex. 818 of them are known by name. A couple of hundred were captured by the Americans. In the trial at Dachau March 7, 1946, 58 of them were sentenced to death, and three of them sentenced to life in prison. All of them plead not guilty. The commandant, Franz Ziereis, was shot by American soldiers in the camp while hiding dressed in civilian clothing.