On 27 July 1944, Adolf Hitler ordered the "Festung Warschau" to be created and defended at all cost. The same day the governor of the General Government, Hans Frank, called for 100,000 Polish men between the ages of 17–65 to arrive at several gathering places in Warsaw the following day. They were to be employed at construction of fortifications for the Wehrmacht in and around the city. This move was viewed by the Armia Krajowa as an attempt to neutralize the underground forces, and the underground urged Warsaw inhabitants to ignore it. Fearing that the city would be turned into ruins and share the fate of Stalingrad and Kiev, General Tadeusz Bór-Komorowski ordered Operation Tempest to be started in Warsaw, which resulted in the Warsaw Uprising that lasted from August through September.