 In April 1945, Hammann, who was the "blockälteste" of the children's barrack, sabotaged the planned movement of Jews on a death march to a certain extermination.Yad Vashem awarded Hammann the title of "Righteous among the Nations".Yisrael Meir Lau, current chairman (as of May 2010) of Yad Vashem Council, was one of the children saved by Hammann.