In 2002, Kaczyński was elected mayor of Warsaw in a landslide victory. He started his term in office by declaring war on corruption. He strongly supported the construction of the Warsaw Uprising Museum and in 2004 appointed a historical panel to estimate material losses that were inflicted upon the city by the Germans in the Second World War (an estimated 85% of the city was destroyed in the Warsaw Uprising) as a direct response to heightened claims coming from German expellees from Poland. The panel estimated the losses to be at least 45.3 billion euros ($54 billion) in current value. He also supported the construction of the museum of Polish Jews in Warsaw by donating city land to the project.