Nacht und Nebel
Himmler immediately communicated Keitel's directive to various SS stations and within six months, the decree was sent to concentration camp commanders by Richard Glücks. The "Nacht und Nebel" prisoners were mostly from France, Belgium, Luxembourg, Denmark, the Netherlands, and Norway. They were usually arrested in the middle of the night and quickly taken to prisons hundreds of kilometres away for questioning, eventually arriving at concentration camps such as Natzweiler, Esterwegen or Gross-Rosen, if they survived. Natzweiler concentration camp in particular, became an isolation camp for political prisoners from northern and western Europe under the decree's mandate. Up to 30 April 1944, at least 6,639 persons had been arrested under "Nacht und Nebel" orders. Some 340 of them may have been executed. The 1956 film "Night and Fog", directed by Alain Resnais, uses the term to illustrate one aspect of the concentration camp system as it was transformed into a system of labour and death camps.