The Soviet Union, despite being one of the victors of World War II ended up having the highest human toll. In addition to the deaths of all the soldiers and military personnel, there were huge numbers of civilian deaths from various causes which might help to explain the high number of deaths.
Some historians and researchers estimate almost seven and a half million Soviet civilians were victims of Nazi genocide. Over seven million deaths have been attributed to famine and disease in both German occupied and non-occupied regions of Russia. And, over two million deaths happened when Russian citizens were deported to Germany as forced laborers under inhuman conditions.