Piet Hoogenkamp was a student of medicine in Utrecht. He refused to sign a declaration of loyalty to the German occupiers and fled to Aalten to join the resistance fighter Dr. Joop der Weduwen. The doctor passed him off as his assistant, using forged papers.
On one occasion, Hoogenkamp was called to a farm in Lintelo to help with a birth. Lena Jedwab-Kropveld was giving birth to her baby in a hiding place, a haystack. She was in a critical state after four days in labor. Piet Hoogenkamp took the little boy to Aalten several hours after his birth. He could not stay with the parents, since the risk of discovery was too great. Piet Hoogenkamp put the baby in a cardboard box outside the home of the Wikkerink family during the night. The family were active in the underground resistance and were aware of the matter. They rescued the child by taking in the apparent “foundling” and registering him under the name of Willem.