Colonel-General Georg-Hans Reinhardt, commander of Army Group Centre, warned of the seriousness of the situation as early as 19 January, but was not permitted to make a phased withdrawal.

[citation needed] To save his units from encirclement, Hossbach started to pull the Fourth Army back to the west in direct contravention of orders, abandoning the prepared defences around Lötzen on 23 January.

[4] As the Nazis had effectively forbidden evacuation of East Prussia's civil population, when the Red Army attacked on 12 January 1945, civilians began a mass flight west to the Baltic sea coast.

At the coast, particularly in the harbour of Pillau, the Kriegsmarine managed to evacuate tens of thousands of civilians over the Baltic sea, and encouraged fierce resistance on land, since every delay to the Red Army meant the rescue of additional old people, women and children.

[8] Ad hoc battle groups were often bolstered by civilians press-ganged into the Volkssturm, and many East Prussian villages and towns had been turned into fortified strongpoints, in addition to the substantial fortifications centred on Heilsberg.

[9] The fighting was prolonged in order to keep open civilian escape routes, and because requests to evacuate the main body of the Fourth Army were refused by the German High Command.

Rosenberg itself was taken on 26 March, with the remnants of the Fourth Army falling back on the Kahlholzer Haken peninsula, where the perimeter was defended by troops from the Panzerkorps "Großdeutschland" and the 28th Jäger Division.

The last evacuations took place on the morning of 29 March from Kahlholz and Balga, where a remnant of the 562nd Volksgrenadier Division was destroyed forming a rearguard (its commander, Helmuth Hufenbach, receiving a posthumous promotion to Major-General).