Otto Ewald Rosenthal was murdered in January 1945 in Łączki, commune Głuchołazy (Ziegenhals) during the death march (presumably from Blechhammer to Gross Rosen).
The entry in the research paper "Registry of places and crimes committed by the German Nazi invaders on Polish territory in the years 1939-1945. Opole Voivodship (Province)" reads:
Łączki, commune Głuchołazy
January 1945
In the vicinity of the village 47 prisoners of Auschwitz have been shot. Among others - Otto Ewald Rosenthal, born August 24, 1903 was killed.The bodies of the victims were buried by inhabitants of the village, then exhumed and moved to a cemetery in Burgrabice on June 25, 1946.