As Erich mentioned, no cremations took place in Mauthausen from 1938 to May 1940. The dead (around 2,100 bodies) were transferred primarily to a crematorium in Steyr, or sometimes to one in Linz. For the proprietors of these public crematoria, the arrangement was lucrative.
In total, three crematoria were built in Mauthausen concentration camp. The first (1940) and second (1942) by H. Kori GmbH, the third by J.A. Topf & Söhne (1945). The SS’s aim was to dispose of as many bodies as fast as possible.
After the war the crematoria were seen as evidence and the Allies documented all details. A small number of managers of Topf & Söhne had to appear before a court due to their involvement in the Holocaust. H. Kori was never the object of extensive examination. Topf & Söhne existed until 1996; H. Kori operated until 2012.
The survivors of the camps quickly established the rooms holding the crematoria as focal points of commemoration. Because of the absence of graves, the furnaces in which the bodies were cremated were and are still used for commemoration.
The designs of some monuments erected in commemoration of the victims have been influenced by the symbols of the crematoria and their chimneys.