Stalin forbade the evacuation of civilians from the city, believing that their presence would encourage greater resistance from the defenders. Civilians, including women and children, were put to work improving the protective fortifications and continuing to work until the end in the tractor factories converted into tank factories.
A massive German aerial bombardment on August 23 caused a veritable firestorm, killing thousands of civilians and turning Stalingrad into a vast landscape of burning rubble and ruins. 80% of the city's habitable space had been destroyed.
The initial commitment to the city's defense fell to the 1077th Anti-Aircraft Regiment, a unit made up mostly of young female volunteers with no ground-engaging target training. Despite this, and without support from other Soviet units, the anti-aircraft gunners remained at their posts and fought off the advancing panzers. The 16th Panzer Division had to fight them until all 37 anti-aircraft batteries were destroyed.
Towards the end of August, German troops reached the Volga north of Stalingrad. Another advance towards the river south of the city followed. The Soviet fighters were therefore surrounded in the city, backed by the Volga, despite various means implemented to circulate on the river.
In the initial phase, Soviet defense was based primarily on "workers' militias" composed of workers indirectly involved in war production. Tanks continued to be produced and equipped by teams of volunteer factory workers. The machines were driven directly from the factory to the front line without even having been painted.
The city soon reached an almost total state of destruction, under the fire of German bombardments. The civilians have deserted the town. Among the debris, the Soviet 62nd Army formed lines of defence, with strongpoints located in houses and factories. The fighting in the city became fierce and desperate. Stalin's Order No. 227, known as "Not a Step Back!" dated July 28, 1942 decreed that anyone who fled or retreated from their positions without orders could be summarily shot. But the Soviets did not really need this propaganda to understand the stakes of this battle and fight heroically. The Germans pushing forward into Stalingrad thus suffered heavily. Soviet reinforcements were embarked across the Volga River from the eastern bank under constant bombardment from artillery and Stukas. The life expectancy of a newly arrived Soviet soldier in the city has dropped to less than twenty-four hours.
German military doctrine was based on the principle of combined arms teams involving close collaboration of infantry, engineers and artillery with air support. To counter this, Soviet commanders adopted a simple technique:always keep the front lines close. This exposed the German infantry to the danger of their own supporting fire, forcing them to limit their use.