while in hiding from the germans during world war ii, wijnkoop suffered a fatal heart attack. many people, including wanted communists, socialists and jews, showed up at his funeral. wijnkoop's wife, johanna van rees, was angry that louis de visser showed up at the funeral while he was wanted, but still asked him to do the graveside speech. it was the last public speech of de visser, who did not survive the war.