Just chiming in, because I had never heard a water heater referred to as a “geyser” before. I was very confused about the application of an electrically heated hole in the ground.

Dinkleberg!!! Russia!!!

The link you decided not to follow gives a lot of context. Although in French, which I do not speak.

These people weren’t murdered at Dachau. They are being cremated there, after dieing aboard the prisoner transport train from the Royallieu-Compiègne internment camp.

The German Wikipedia about the Sonderkommando photographs describes those as the only surviving photos taken by prisoners inside the camps.