In November 1942, resistance fighter Helena Kuipers-Rietberg started setting up an organisation to help people go into hiding. Through her work for a Christian women's organisation, she knew many people. That same month, she asked the Reverend Frits Slomp for help. He was very much opposed to the Nazis and travelled across the Netherlands to find hiding addresses and host families.
In the course of 1943, the National Organisation to Help Those in Hiding - the LO for short - arose from this network. Many existing resistance groups joined the LO. The LO arranged hiding addresses for Jews and for young men who did not want to work for the Nazis.
Later on, National Fighting Squads (Landelijke Knokploegen) were erected that would, for instance, raid distribution offices to steal food stamps for people in hiding.
In August 1944, Helena Kuipers-Rietberg and her husband were arrested by the Sicherheitsdienst. During the interrogation, she took all the blame to make sure that her husband was released. Helena ended up in German concentration camp Ravensbrück. Weakened by illness, she died there on 27 December 1944.