- Albertus "Bertus" Willemsen was born in Oosterbeek. He was a son of Evert Willemsen and Catherina Hendrika Willemsen (née Minkman). His mother died on 18 november 1928.
According to Cor Janse, author of the book Blik Omhoog, Willemsen lived with his father at Steenenkruis 48, Oosterbeek. On 17 september 1944 he was standing in the doorway of the house when the 388th Bomb Group of the US Air Force bombed a flak position west of the railwaybridge at Oosterbeek.
Willemsen was buried in a mass grave in the Oude Begraafplaats (Old Cemetery) at the Fangmanweg at Oosterbeek. He was reburied in Oosterbeek General Cemetery, in a collective grave in a plot for civilian casualties of WW II.