ONUC
On 18 September 1961, Hammarskjöld was en route to negotiate a cease-fire between United Nations Operation in the Congo forces and Katangese troops under Moise Tshombe. His Douglas DC-6 airliner SE-BDY crashed near Ndola, Northern Rhodesia (now Zambia). Hammarskjöld perished in the crash, as did all but one of the 16 passengers, who died from injuries a few days later. Hammarskjöld's death set off a succession crisis at the United Nations, as there was no line of succession and the Security Council had to vote on a successor.