WARSAW, Poland — Sirens wailed and traffic in downtown Warsaw stopped for a minute on Thursday to honor the thousands of people who died trying to liberate the city from Germany's Nazi forces during World War II. This year some observances were shown live on Facebook for the first time.

The Warsaw Rising Museum's Facebook page showed people honoring their fallen heroes. On Aug. 1, 1944, thousands of residents — chiefly young people — began trying to free Warsaw from the Germans while the Soviet Red Army advanced toward the city as it was pushing the Nazis out of Eastern Europe.

A few dozen thousand poorly armed fighters of Poland's clandestine Home Army fought for 63 days against the incomparably larger German land and air forces. Some 200,000 civilian residents and fighters were killed in the fighting, and the Germans razed the city.

Later, when Poland was under communist control, recognizing that historic event was forbidden, chiefly because the Home Army also had fought against Soviet rule.

But on Thursday surviving veterans, President Bronislaw Komorowski, Prime Minister Donald Tusk and other leaders laid wreaths at the monument in Warsaw to the fighters at Powazki cemetery, where many of them are buried.