One of the readers of my blog wrote the following in a comment:
“Yes, there were machines to crush bones [in the concentration camps]. The prisoners also manually crushed any remaining bones.”
I wrote about bone crushing in the camps on my website.
Begin quote from my scrapbookpages.com website:
Another member of the Sonderkommando who survived was Henryk Mandelbaum who arrived at Auschwitz-Birkenau in April 1944.
The following quote is from The Toronto Star on June 21, 2008:
Soon after a 21-year-old Henryk Mandelbaum arrived at Auschwitz-Birkenau in April 1944, he was taken to a gas chamber filled with the lifeless bodies of fellow Jews.
He would become accustomed to the sight. During more than nine months as a member of the Sonderkommando, the group of prisoners the Nazis forced to assist in the disposal of the gassed, Mandelbaum “saw everything from beginning to end,” said Auschwitz-Birkenau museum historian Igor Bartosik “people going into the changing rooms, he saw people changing, he saw the moment of the gassing, the throwing of the Zyklon into the gas chambers, he heard the screams.”
Mandelbaum’s daily routine: help remove hair, gold teeth and hidden jewelry from the dead; carry them to the crematoria; load them into the ovens.
“I thought,” he said in 2006, “I was in hell. Fire and smoke were everywhere. I had to clean the gas chambers and put the bodies in the crematoria, or burn them outside when the extermination was in full swing and the crematoria were not enough … we then had to crush the bones into powder and throw it in the river.”
Sonderkommando members were habitually executed. Fewer than 150 of more than 2,000 who served in the group at Auschwitz-Birkenau survived. But Mandelbaum escaped during a January 1945 “death march,” then spent decades speaking about his experience and leading group tours of the camp.