18 September 1961
United Nations (UN) Secretary General Dag Hammarskjold was killed with twelve other people when their plane crashed at Ndola airport, Northern Rhodesia (now Zambia). Hammarskjold was on his way to meet with President Moise Tshombe of Katanga Province in Congo in an attempt to end the fighting in Katanga. UN officials in Elisabethville were stunned when they received reports that Hammarskjold had not arrived in Ndola. Associated Press reported that the lone survivor, Harold M. Julian, a United Nations security guard, said that a series of explosions had preceded the crash. He also said that the plane had turned away from a landing, apparently on Mr Hammarskjold's orders. His death was a terrible blow to hopes for a truce in Katanga.
References

Hergaty S. Dag Hammarskjold: Was his death a crash or a conspiracy? from BBC News(17 September 2011)[online] Available at: www.bbc.co.uk [Accessed on 18 September 2013]|

Wallis, F. (2000). Nuusdagboek: feite en fratse oor 1000 jaar, Kaapstad: Human & Rousseau;