The Soviets bore the brunt of World War II because the West did not open up a second ground front in Europe until the invasion of Italy and the Battle of Normandy. Approximately 26.6 million Soviets, among them 18 million civilians, were killed in the war. Civilians were rounded up and burned or shot in many cities conquered by the Nazis. The retreating Soviet army was ordered to pursue a 'scorched earth' policy whereby retreating Soviet troops were ordered to destroy civilian infrastructure and food supplies so that the Nazi German troops could not use them.