​​In mid-August 1944, with Allied forces approaching, acts of resistance intensified in occupied Calais. On 16 August, eight armed individuals broke into the Brampton factory, damaging the telephone exchange and setting fire to the transformer room. The sabotage targeted an industrial site that supplied both the French and German markets. In response, the German Feldgendarmerie tightened security and imposed a strict curfew.

​Lacking leads, the Gestapo and Kriegsmarine Security Service initiated a broad investigation. Interrogations led to the arrests of Jean Bodechon, Alfred Véron, Alfred Legros, Fernand Gouverneur, and Roland Le Gal. Some had participated in the factory sabotage, while others were linked to a separate act of resistance involving the sabotage of German trucks in March 1944. Despite limited evidence, confessions were extracted under torture by Oberfeldwebel Rudolph Herzog.

​Robert Dérain, initially detained, escaped from hospital custody and later reappeared among evacuees during the liberation. Ironically, he identified Herzog—disguised with an FFI armband—among the fleeing civilians.

​The five young men from Calais were executed in secret by German forces, and their fate remained unknown. After the city's liberation, their families searched for answers. In 1947, investigations resumed with the help of Inspector Paul Dagbert and former SOE officer Lieutenant-Colonel Buckmaster. Interrogations of German prisoners, including Oberleutnant Albin Kellner, revealed the location of the burial site in the ruins of the citadel.

​On 11 October 1947, after extensive digging, the bodies were recovered and identified through personal belongings. The city of Calais announced a public tribute the following day to honour the resistance fighters executed without trial.

​Today, a memorial stele stands at the citadel, marking the site where the five men were buried. Each year, on 3 September, Calais commemorates their sacrifice with a ceremony at the memorial, preserving the memory of those who resisted occupation at the cost of their lives.