In 1944 Planck's son Erwin was arrested by the Gestapo following the attempted assassination of Hitler in the 20 July plot. He was tried and sentenced to death by the People's Court in October 1944. Erwin was hanged at Berlin's Plötzensee Prison in January 1945. The death of his son destroyed much of Planck's will to live. After the end of the war Planck, his second wife, and his son by her were brought to a relative in Göttingen, where Planck died on 4 October 1947. His grave is situated in the old Stadtfriedhof (City Cemetery) in Göttingen.