Elie Mozes de Metz, the youngest and still unmarried son of Abraham de Metz and Bertha van Leeuwen was put to work at the Rijks Werkkamp Echten, in the summer of 1942, which was located at the highroad Ruinen-Echten in the province of Drenthe. This camp had two barracks, each for 48 pesons, a kitchen and a dwelling for the cook/administrator, a relexation room, a lavatory, a petrol station a a bicycle place and a toilet building.
In the night of 2-3 October 1942 (during Yom Kipur), making them believe of a family reunion, the Jews were taken from the labor camps and deported via camp Wersterbork to the extermination camps. Also Elie Mozes de Metz came in Westerbork then too, where he had to stay till 26 October 1942. That day he was put on transport to Auschwitz and on arrival there, he was selected for hard labor in the camp. It is not known whether Elie Mozes was killed in the gas chambers or that at some point he has lost his life due to illness, hardship or exhaustion. His official date of death has been established as 28 February 1943.
Sources: City Archive of Amsterdam, archive card of Abraham de Metz; labour camp Echten: https://www.joodsewerkkampen.nl/Werkkamp/4-echten.html; labourcamps in general: https://nl.wikipedia.org/wiki/Joodse_werkkampen; and the file cabinet of the Jewish Council, registration card of Elie Mozes de Metz.