UN Leader Dag Hammarskjold Died in Mysterious Circumstances in 1961. What Really Happened? New evidence supports a theory that the pioneering U.N. secretary general was assassinated. https://www.history.com/news/dag-hammarskjold-death-plane-crash https://www.theguardian.com/world/2011/aug/17/dag-hammarskjold-un-secretary-general-crash https://www.nytimes.com/2019/10/08/world/africa/dag-hammarskjold.html