Under Constrtion 

Civilian Deaths 
WWII 
 50 to 55 M, including 19 to 28 million from war-related disease and famine.

  
 Allied country Deaths
    5 - 6 M Holocaust (almost 2/3 of the Jewish population in Europe)
   13 - 15 M Russians
   11 M China

 Axis country Deaths
  25-60 K in the Bombing of Dresden
  88-200 K in the Bombing of Tokyo
  90-146 K in the A-bomb over Hiroshima *
  39-80 K in the A-bomb over Nagasaki *
  242-486 K Total
  
  * Roughly half of the deaths in Hiroshima and Nagasaki occurred on the first day.
   During the following months, large numbers died from the effect of burns,
   radiation sickness, and other injuries, compounded by illness and malnutrition.
  See Atomic bombings of Hiroshima and Nagasaki - Wikipedia

    World War 2 Statistics
  
2M Vietnam 
A 2008 study by researchers from Harvard Medical School and the
Institute for Health Metrics and Evaluation at the University of Washington
and a Vietnamese government estimate, suggest there were around two million
civilian deaths, the vast majority in South Vietnam
 
 
 Links
 World War II casualties - Wikipedia
last updated 8 Nov 2017