Stalingrad, a Soviet city and industrial centre on the river Volga, was bombed heavily by the Luftwaffe during the Battle of Stalingrad in World War II. German land forces comprising the 6th Army had advanced to the suburbs of Stalingrad by August 1942. The city was firebombed with 1,000 tons of high explosives and incendiaries in 1,600 sorties on 23 August. The destruction was monumental and complete, turning Stalingrad into a sea of fire and killing thousands of civilians and soldiers. Further fire-attacks were mounted against the ruined city for the next two days, enveloping it in dense volcano-like black smoke clouds that stretched 3.5 kilometers into the sky.