The Germans in the Stalingrad cauldron reject the Soviets' final offer of surrender. The Red Army responds by crushing the cauldron. 

Map 1: The end of the Kessel

Source: Military History Now 

The ultimatum to Stalingrad: 

https://www.stalingrad.net/russian-hq/the-russian-ultimatum/rusultimatum.html 

Images:

3-engine German transport plane lands at Pitomnik airfield.

Red Army soldiers attack in the ruins of Stalingrad.

Sources:

Antony Beevor, Stalingrad: The Fateful Siege 1942–1943. Penguin Books, 1998.

Antony Beevor, The Second World War. London, UK: Little, Brown and Co., 2012.

William Craig, Enemy at the Gates: The Battle for Stalingrad. Old Saybrook, CT, USA: Konecky & Konecky, 1973.

Anthony Tucker-Jones, Slaughter on the Eastern Front: Hitler and Stalin’s War 1941–1945. Stroud, Gloucestershire, UK: The History Press, 2017

Sound effects by Zapsplat.