A civil engineer by profession, he was head of the SS Central Building Administration at Lublin reservation in occupied Poland.

Thomalla was in charge of construction for the Operation Reinhard death camps Bełżec, Sobibor and Treblinka during the Holocaust in Poland.

Born in Annahof in the former Upper Silesia region of the German Empire (now, the village of Sowin, Opole Voivodeship, Poland).

Workers employed for building the camp were local people from neighboring villages and towns.

[4] When Thomalla completed his building assignment in Sobibor he was replaced there as commandant by Franz Stangl in April 1942.