Auschwitz II - Birkenau was a gigantic and horrific factory of death, built for the purpose of extermination on the site of the evacuated village of Brzezinka. With 300 buildings, many of them wooden, housing 100,000 prisoners. The living conditions here were terrible, with plagues of rats, lice and fleas; with inadequate water supplies and sanitary conditions. Prisoners arrived in freight trains directly into the camp on railway lines extended by the Nazis to within a short distance of the gas chambers. At the height of the genocide, many thousands of people were murdered every day and there are areas in Birkenau where the ground is composed of deep layers of human ashes.