They concluded that it must have an extremely long half life, perhaps millions of years. Part of the problem was that they still believed that element 94 was a platinoid, which confounded their attempts at chemical separation. World War II On 24 April 1939, Paul Harteck and his assistant, Wilhelm Groth, had written to Reich Ministry of War, alerting it to the possibility of the development of an atomic bomb. In response, the Army Weapons Branch (HWA) had established a physics section under nuclear physicist Kurt Diebner. After World War II broke out on 1 September 1939, the HWA moved to control the German nuclear weapons program. From then on, Hahn participated in a ceaseless series of meetings related to the project. After the Director of the Kaiser Wilhelm Institute for Physics, Peter Debye, left for the United States in 1940 and never returned, Diebner was installed as its director. Hahn reported to the HWA on the progress of his research. Together with his assistants, Hans-Joachim Born, Siegfried Flügge, Hans Götte, Walter Seelmann-Eggebert and Strassmann, he catalogued about one hundred fission product isotopes. They also investigated means of isotope separation; the chemistry of element 93; and methods for purifying uranium oxides and salts. On the night of 15 February 1944, the Kaiser Wilhelm Institute for Chemistry building was struck by a bomb. Hahn's office was destroyed, along with his correspondence with Rutherford and other researchers, and many of his personal possessions. The office was the intended target of the raid, which had been ordered by Brigadier General Leslie Groves, the director of the Manhattan Project, in the hope of disrupting the German uranium project. Albert Speer, the Reich Minister of Armaments and War Production, arranged for the institute to move to Tailfingen in southern Germany. All work in Berlin ceased by July. Hahn and his family moved to the house of a textile manufacturer there. Life became precarious for those married to Jewish women. One was Philipp Hoernes, a chemist working for Auergesellschaft, the firm that mined the uranium ore used by the project. After the firm let him go in 1944, Hoernes faced being conscripted for forced labour. At the age of 60, it was doubtful that he would survive. Hahn and Nikolaus Riehl arranged for Hoernes to work at the Kaiser Wilhelm Institute for Chemistry, claiming that his work was essential to the uranium project and that uranium