In February 1942 he was promoted to the rank of SS-Obersturmführer and transferred to Amtsgruppe C (Buildings and Works) at the SS-Main Economic and Administrative Office in Berlin.
[1] Hack oversaw hundreds of slave-laborers who were employed in building a large subterranean aircraft engine factory that would be used to produce components for Germany’s V-2 guided missiles.
At Berga he again directed slave-labor by concentration camp prisoners,[2] this time using inmates from Buchenwald to dig mining tunnels for use in synthetic oil production.
The casualties among this group were severe, with at least 55 Americans dying as a result of disease or malnutrition in just the few months they spent in the camp.
Hack was initially able to avoid capture following the German surrender in 1945, but was eventually arrested by Soviet occupation authorities in the city of Zwickau in 1947.