During the Holocaust, the Nazis targeted seven major groups: Jews, Romas (gypsies), homosexuals, Slavs, mentally and physically handicapped, Jehovah's Witnesses, and Soviet Prisoners of war.
They would dig a shallow hole in the ground and throw the bodies inside. When the bodies reached the top, they would cover the hole back up and dig a new one.
It was seen by the perpetrators of this war crime to be an efficient and cost effective method of destroying Jews, Gypsies, Homosexuals, Communists and many other humans that the Nazi regime regarded...