Tuberculosis was still rife in The Netherlands in the twentieth century, and in 1918, a sanatorium was built in Gennep to provide care for sufferers of this disease. In the years that followed, the Mariaoord sanatorium grew into a health resort with more than one hundred beds and a separate health resort for aftercare called 'Zon-licht-heide' (Sun-light-heath). Then when the front lines came to a standstill at the end of September 1944, military forces started evacuating the people. This included the residents of Gennep in the week starting the 15th October 1944.

However, the Mariaoord sanatorium and 'Zon-licht-heide' health resort were not evacuated out of fear of infection and a complicated evacuation procedure. Consequently, the resorts turned into two inhabited islands in an otherwise deserted village. Evacuees from the surrounding area were given (temporary) shelter there, but with the front lines so close by, it was not uncommon for the occasional British shell to fall nearby, like the one that hit the children's ward on 30th October 1944. In December 1944, after the St. Nicholas celebrations, both of these institutions were evacuated. The patients were taken to Winterswijk.