Information: Wikipedia

A Stolperstein literally "stumbling stone", metaphorically a "stumbling block" is a sett-size, 10 by 10 centimetres (3.9 in × 3.9 in) concrete cube bearing a brass plate inscribed with the name and life dates of victims of Nazi extermination or persecution.

The Stolpersteine project, initiated by the German artist Gunter Demnig in 1992, aims to commemorate individuals at exactly the last place of residency—or, sometimes, work—which was freely chosen by the person before he or she fell victim to Nazi terror, euthanasia, eugenics, was deported to a concentration or extermination camp, or escaped persecution by emigration or suicide. As of 29 March 2018, over 67,000 Stolpersteine have been laid in 22 countries, making the Stolpersteine project the world's largest decentralized memorial.

The majority of Stolpersteine commemorate Jewish victims of the Holocaust. Others have been placed for Sinti and Romani people (then also called "gypsies"), homosexuals, the physically or mentally disabled, Jehovah's Witnesses, black people, members of the Communist Party, the Social Democratic Party, and the anti-Nazi Resistance, the Christian opposition (both Protestants and Catholics), and Freemasons, along with International Brigade soldiers in the Spanish Civil War, military deserters, conscientious objectors, escape helpers, capitulators, "habitual criminals", looters, and others charged with treason, military disobedience, or undermining the Nazi military, as well as Allied soldiers.

Frerik Bart van Itallie was born in Middelburg, 3 September 1941 and died in Auschwitz, 8 April 1944. He reached the age of 2 years.

Anna Wilhelmine van Itallie-van Raalte was born in Vlissingen, 6 February 1912 and died in  Auschwitz, 8 April 1944. She reached the age of 32 years.

Sara Polak-Braasem was born in Middelburg, 6 December 1869 and died in  Auschwitz, 26 February 1943. She reached the age of 73 years.

Sara was a daughter of Mouritz Braasem and Rebekka Bartha van Oss. She married Lion Polak in 1897 in Middelburg, he died in 1937. They had four children: Simon, Henriette and two children who survived the war.

Abraham van Dam was born in Sint Laurens, 31 October 1935 and died in Auschwitz, 21 September 1942. He reached the age of 6 years.

Philip Isaac van Dam was born in Rotterdam, 22 May 1912 and died in Auschwitz, 31 December 1942. He reached the age of 30 years. He was a salesman. Philip Isaac van Dam was a son of Abraham van Dam and Emma Goldstein.  He had an older brother, Samuel, and a younger sister, Duifje van Haren-van Dam, who both survived and moved to British Columbia Canada after the war.

Henriette van Dam-Polak was born in Middelburg, 6 April 1913 an died inAuschwitz, 21 September 1942. She reached the age of 29 years. Henriette was a daughter of Lion Polak and Sara Braasem. She married Philip Isaäc van Dam in 1934.

Henri Heertje was born in Amsterdam, 15 August 1913 and died in Sobibor, 23 July 1943. He reached the age of 29 years and was a schoolteacher.  Henri  was the son of Meijer Heertje and Engeltje Croonenberg. He was married to Evalina Schoolmeester. Henri earned a doctoral degree. His thesis, ‘De diamantbewerkers van Amsterdam’ (The diamond workers of Amsterdam) was published in 1936.

Evalina Heertje-Schoolmeester was born in Amsterdam, 24 November 1915 and died in Sobibor, 23 July 1943. She reached the age of 27 years.  Evalina was a daughter of Nathan Schoolmeester and Hendrika Konijn.