German Chancellor Gerhard Schroeder, U.S. Secretary of State Colin Powell and British Deputy Prime Minister John Prescott were due to attend ceremonies Sunday evening in Warsaw marking the 60th anniversary of the August 1st outbreak of the doomed 1944 Warsaw Uprising against the Nazis. Regarded as one of the bloodiest battles in Polish history and the largest partisan assault against the Nazis anywhere in WWII occupied Europe, the 63-day-long rebellion was launched by some 40,000 poorly-armed Polish Home Army (AK) insurgents loyal to Poland's government-in-exile in Britain in a bid to repel the Nazis from Warsaw ahead of the arrival of the advancing Soviet Red Army. The Germans crushed the Polish insurgents after Soviet dictator Josef Stalin refused to back the revolt with nearby Red Army troops and prevented Britain and the United States from flying-in vital support. Some 18,000 insurgents and 180,000 civilians were slaughtered. On orders of Nazi German dictator Adolf Hitler, Warsaw was then systematically bombed until hardly a building was left standing.