On 18 September 1961 Hammarskjöld flew to Ndola , just across the border in Northern Rhodesia , to attempt to broker a cease-fire between UN and Katangese forces . His aircraft crashed before landing at Ndola Airport , killing him and everybody else on board . In stark contrast to Hammarskjöld 's attempts to pursue a moderate policy in the Congo , his successor U Thant supported a more radical policy of direct involvement in the conflict . Katanga released the captured Irish soldiers in mid-October as part of a cease-fire deal in which ONUC agreed to pull its troops back — a propaganda coup for Tshombe . Restated American support for the UN mission , and the murder of ten Italian UN pilots in Port-Émpain in November 1961 , strengthened international demands to resolve the situation . In April 1962 UN troops occupied South Kasai . On the night of 29/30 September 1962 , South Kasai military commanders launched a coup d'état in Bakwanga against the Kalonjist regime . On 5 October 1962 , central government troops again arrived in Bakwanga to support the mutineers and help suppress the last Kalonjist loyalists , marking the end of South Kasai 's secession
His aircraft crashed
1961 Ndola United Nations DC-6 crash
Congo Crisis