MOSCOW –  The Soviet soldiers used their own bodies as shields, covering women and children escaping on ferry boats from a Nazi bombardment that killed 40,000 civilians in a single day. It was the height of the Battle of Stalingrad, one of the bloodiest conflicts of World War II.

"They were all hit in the back," said 90-year-old Alexei Stefanov. "But they did not flee."

Stefanov is among the few surviving veterans of the battle, which claimed 2 million lives and raged for nearly 200 days before the Red Army turned back the Nazi forces, decisively changing the course of the war. Russia celebrates the 70th anniversary of that victory on Saturday, with President Vladimir Putin taking part in ceremonies in Volgograd, the current name of the city in southern Russia that stretches along the western bank of the Volga River....