6. The steady pressure applied by the Germans forced the Poles to abandon some areas by September
Some of the fiercest fighting during the Warsaw Uprising occurred in August in the section of the city known as Old Town. Old Town and City Center were part of the section of the city which had been designated as Area 1 by the planners of the attack, which was never fully secured during the early days of the fighting. Fortified pockets of German defenders remained throughout August, and the areas held by the Poles were subjected to some of the heaviest German artillery fire and aerial bombing. At the end of September the Polish leadership decided to abandon Old Town, and the district was evacuated via the sewers over the course of two days, with the Home Army units withdrawing at night. They took with them as many of the civilians remaining in the area as they could, though some elected to remain in their homes.
Those who remained were taken by the Germans, with any suspected of having supported the resistance fighters shot by the SS. Those that were not, including children, were sent to concentration camps in the aftermath of the fighting, most of them to Mauthausen and Sachsenhausen. Meanwhile the Red Army, which had been concentrating on seizing bridgeheads on either side of Warsaw, finally determined that the Germans had destroyed most of them and were preparing to withdraw all of their forces in the region to the western side of the Vistula, making Warsaw once again of some importance to the advance of the Soviets. The Polish 1st Army, under Soviet command and equipped with largely Soviet weapons, was dispatched to establish contact with the Home Army.