The Polish Home Army (AK) was a resistance force of 150,000, loyal to the London Based Polish Government in exile. In August 1944 they planned to take the city from the Germans before the Russians arrived.
The Germans sent their crack troops to resist the Russians and crush the uprising.
A quarter of a million civilians died from the shelling, dive bombing and wholesale massacres.
Britain and America sent planes from Italy to drop supplies for the civilian population but with little effect. They couldn't come to the aid of the resistance fighters as Russia by this time had joined the Allies
The AK capitulated on 21/10/44 and the surviving inhabitants were evacuated when Hitler ordered that Warsaw should be 'razed without trace'
Most of the apartment blocks were bombed, shelled or set on fire.
The evacuees were sent to special selection and distribution centres were they were 'sorted' to go to either concentration camps or sent to work in the Polish countryside.