Warsaw today commemorated the 72nd anniversary of the uprising of the population of that Polish city against Nazi occupation, the largest armed operation of the resistance movements throughout Europe taken by the Nazis.At 1700 local time (15.00 GMT) the Polish capital was paralyzed in a silence broken only by the sound of sirens and church bells, who remembered well the exact time when the uprising began on August 1, 1944 silence ."The Warsaw Uprising is a monument of our collective memory and insurgents are our greatest treasure," said Polish President Andrzej Duda, during a speech.Earlier, representatives of the Polish Government laid flowers at the Tomb of the Unknown Soldier in Warsaw, within the day to commemorate the uprising which also included several survivors of the uprising.The operation ended after 63 days of heavy fighting, leaving 200,000 dead, 83% of the buildings in the devastated city and the capitulation of the insurgents.