Description:Russia prepares to mark the 70th anniversary of victory at Stalingrad -- the deadliest battle of World War Two. The battle lasted for almost a year with relentless bombing, tank fire and heavy artillery. Some 300,000 elite German troops died in two and a half months as much from Soviet firepower as hunger and freezing temperatures. The Germans surrendered on Feb. 2, 1943. Now the wars veterans say the battle offers lessons for generations.(1:34)