[Kenneth R. Wilson] The 'False News' Trial of Ernst Zündel -- 1988 

MORGUE CELLARS OF BIRKENAU:

Quotes
In order to get an idea of the several Leichenkeller at Birkenau, Pressac ought to have visited the Leichenkeller at the Sachsenhausen concentration camp, which is still intact and which, modernized in 1940/1941, offers a standard model of this type of building: on the ground floor there was a dissecting room, a doctor's office, etc., and in the basement three rooms occupying about 230 square meters. They could hold 200 corpses. Each room had its own function. One was designed for the undressing and laying out of 80 corpses; the next for laying out 100 corpses; the third was for 20 infected corpses. It is not claimed that there was a homicidal gas chamber in the Sachsenhausen crematorium. Pressac could have verified on the spot that a Leichenkeller, which has to be cool, possesses as well heating vents, humidification equipment, a special system for the isolation of the infected corpses (no direct drainage into the sewage system), a chute (Rutsche) very similar to those in Krema II and III at Birkenau with, on both sides, steps for the personnel who ran the elevator for transporting the corpses. Finally, at Sachsenhausen it is confirmed that the very word Leichenkeller is generic and is used of the building, ground floor and cellar, as a whole. This point of nomenclature alone should make us cautious regarding every invoice, every work sheet, every accounting record which, apparently referring to a basement room, perhaps actually concerns a room on the ground floor. For example, at Sachsenhausen the well-lit dissecting room or the doctor's office, both located on the ground floor, are described as belonging to a Leichenkeller (underground morgue). AUSCHWITZ: TECHNIQUE & OPERATION OF THE GAS CHAMBERS Or, Improvised Gas Chambers & Casual Gassings at Auschwitz & Birkenau, According to J.-C. Pressac (1989) by ROBERT FAURISSON

"Execution room" in basement of crematorium building Buchenwald.  This is an underground morgue.

Some of the Buchenwald prisoners told the American liberators that the hooks were used to hang the bodies to keep them straight before rigor mortis set in. At Dachau, the bodies were hung in front of the ovens to keep them straight before they were cremated. Buchenwald Survivors