Lottner was Kampfkommandant of Lübeck in April/May 1945. On 2 May, British troops prepared to conquer Lübeck. Lottner, NSDAP-Kreisleiter Bernhard Clausen, mayor Otto-Heinrich Drechsler, Police chief Walther Schröder and officers in place agreed that a fight against the advancing 11th Armoured Division was senseless. They gave orders to remove the explosive charges already put in place at bridges and harbour facilities.[1][2]
Fellgiebel, Walther-Peer (2000) [1986]. Die Träger des Ritterkreuzes des Eisernen Kreuzes 1939–1945 — Die Inhaber der höchsten Auszeichnung des Zweiten Weltkrieges aller Wehrmachtteile [The Bearers of the Knight's Cross of the Iron Cross 1939–1945 — The Owners of the Highest Award of the Second World War of all Wehrmacht Branches] (in German). Friedberg, Germany: Podzun-Pallas. ISBN978-3-7909-0284-6.