Twenty children of disparate nationalities were selected by Joseph Mengele as human subjects for medical experimentation by Kurt Heissmeyer at the Neuengamme concentration camp near Hamburg.

Although almost initially lost in the wake of WWII, the story and identity of the children was ultimately uncovered through the research of German journalist, Günther Schwarberg (1926-2008) and his wife, attorney Barbara Hüsing.

[5] On the street where Sergio De Simone's family lived in Naples, a memorial plaque and a pavement Stolperstein mark his life, which is commemorated annually on 27 January International Holocaust Remembrance Day.

De Simone's mother, of Jewish origin, was born on 23 September 1904 in Vidrinka, a town that no longer exists (possibly in Belarus, though more likely, Ukraine).

[6] In August 1943, with her husband called to the Navy (later taken to Dortmund as slave labor) and Italy having entered the war alongside Nazi Germany, Gisella Perlow was alone with her six-year-old son in Naples, which now experienced heavy bombings and where she risked being discovered in the hunt for Jews, by Nazi-fascists.

[7][8] The Perlow family was taken to the Risiera di San Sabba concentration camp and immediately joined the group of deportees leaving on 29 March and arriving in Auschwitz after six days in by convoy.

[9] Having been chosen in November 1944 by Joseph Mengele as one of the twenty children (10 boys and 10 girls) to be sent to the Neuengamme concentration camp, Sergio was made available as a human subject in Kurt Heissmeyer's tuberculosis experimentation.

[11] On 29 November 1944, Sergio's seventh birthday, he and 19 other children, from France, the Netherlands, Yugoslavia, and Poland, arrived at the Neuengamme concentration camp,[12] accompanied by Dr. Paulina Trocki and three nurses.

[13] In Neuengamme the children were entrusted to four deportees, charged with taking care of the group: the French doctors, René Quenouille and Gabriel Florence, and two Dutch nurses, Anton Hölzel and Dirk Deutekom.

On 9 January 1945 Heissmeyer began the experiments: he had the skin on the chest of 11 children, under the right armpit, incised with X-shaped cuts, three to four centimeters long, to introduce tuberculosis bacilli with a spatula[15] — causing rapid spread of the disease.

In early March the children, sick and feverish, were operated on to remove their axillary lymph nodes, which according to the doctor's theories should have produced antibodies against tuberculosis.

A series of twenty surviving photographs document the operations; they show each child, shaven and shirtless, presenting their raised arms and their under-arm incisions.

[16] The experiment had failed: the removed lymphatic glands were sent to Hans Klein, a pathologist at the Hohenlychen clinic, who on 12 March 1945 certified to Heissmeyer that no antibodies had been generated.

At 10pm on the evening of 20 April, the children, their four adult caretakers and several Soviet prisoners were loaded into a mail truck and driven the approximately 30 kilometers from the Kinderblock hut 4a, the site of the experimentation, to Bullenhuser Damm — along with Wilhelm Dreimann, Adolf Speck, Heinrich Wiehagen, their executioners, so-called SS doctor Alfred Trzebinski and Johann Frahm, German SS sergeant.

"[4] Sergio's two cousins, sisters Anda and Tatiana (Tati) Bucci, survived and were initially relocated to Lingfield in England via Prague.

"[9] In April 1946 the main material perpetrators of the massacre, including Commander Max Pauly, who gave the final orders, were tried by an English court and sentenced to death, carried out in October 1946.

[6] Although the responsibilities of Kurt Heissmeyer were brought to light in the trial, the German doctor was not indicted because he was not present at the massacre; he would continue his medical career unimpeded.

Though a small group of ex-Neuengamme fellow prisoners continued to bring flowers each year to Bullenhuser Damm, collective memory of the massacre itself had almost been lost.

In 1959, German journalist Günther Schwarberg published a series of articles dedicated to the massacre in the weekly Stern, implicating Heissmeyer.

Obersturmbannführer Arnold Strippel, the highest-ranking Nazi criminal involved in child murder, was sentenced to life imprisonment in 1949, but was released in 1969 and even received around 120,000 marks in compensation.

In 1980 (expanded in 2010–11), the cellar at the Bullenhuser Damm School was made a Holocaust museum, where the other children and adult victims of the massacre are commemorated.

[22] In 2022, a small engraved memorial Stolperstein or stumbling block (Italian: pietra d’inciampo) was inlaid in front of his family's Vomero residence, in a ceremony attended by Sergio's younger brother Mario de Simone (born in 1946, after the war).

Debuting on the occasion of the 80th anniversary of the fascist racial laws in Italy, the 30-minute film, directed by Rosalba Vitellaro and Alessandro Belli, was presented at the International Animation Festival on the Bay, held in 2018 in the Piedmontese capital.