Klingenberg, a company commander in the Das Reich division, led his unit to the capital, Belgrade, where a small group in the vanguard accepted the surrender of the city on 13 April.

Jevrem Tomić, the Mayor of Belgrade, came out to meet them, after Klingenberg bluffed, telling him there was an incoming artillery barrage and an impending Luftwaffe attack.

[3] [4][5] The German army eventually arrived, dumbfounded at the situation, having made a complex plan to take the city that was no longer needed, and was expected to cost thousands of lives.

On 21 December 1944, Fritz Klingenberg was promoted to SS-Standartenführer and two weeks later (on 12 January 1945) was appointed to command the SS Division Götz von Berlichingen.

[citation needed] On 23 March 1945, Klingenberg was killed by a tank shell during a firefight on the western edge of Herxheim and is buried at the German War Cemetery in Andilly, France.