Wikipedia
The Rheinwiesenlager , were a group of 19 camps built in the Allied-occupied part of Germany by the U.S. Army to hold captured German soldiers at the close of the Second World War. Officially named Prisoner of War Temporary Enclosures (PWTE), they held between one and almost two million surrendered Wehrmacht personnel from April until September 1945. Prisoners held in the camps were designated Disarmed Enemy Forces not POWs. The decision had been taken in March 1943 by SHAEF commander in chief Dwight D. Eisenhower because of the logistical problems adhering to the Geneva Convention (1929). By not classing the hundreds of thousand of captured troops as POWs, the problems associated with accommodating so many prisoners of war according to international treaties governing their treatment was negated.
Most estimates of German deaths in these camps range from 3,000 to 10,000. Many of these died from starvation, dehydration and exposure to the weather elements because no structures were built inside the prison compounds.