Sachnowitz attended the death march from the camp in Buna on 18 January 1945, and they walked 80 km the first day.
From Gliwice they were sent with train which went all over the present-day Czech republic and Austria and finally arrived in the camp at Dora at Nordhausen after approximately 10 days.
Sachnowitz was a witness of the many bodies, which each only weighed 35–40 kg, which were burnt outside the camp in huge fires or sent to the crematorium at Buchenwald.
Sachnowitz told about his stay as a Jewish slave in Auschwitz in the book Det angår også deg (It concerns you too), co-written by Arnold Jacoby.
His late brother Elias had opened a ladies' clothing store "Ekko" (Prinsegata 8) in Larvik in 1935, that Herman now took over.