The German offensive to capture Stalingrad, a major industrial and transport hub on the Volga River that ensured Soviet access to the Caucasus oil wells, began in August 1942, using the 6th Army and elements of the 4th Panzer Army. The attack was supported by intense "Luftwaffe" bombing that reduced much of the city to rubble. The battle degenerated into house-to-house fighting, as both sides poured reinforcements into the city. By mid-November, the Germans had pushed the Soviet defenders back at great cost into narrow zones along the west bank of the river.