Overview
On September 18, 1961, UN Secretary-General Dag Hammarskjöld was traveling to negotiate a ceasefire in the Congo when his DC-6 aircraft crashed near Ndola, Northern Rhodesia (now Zambia). While early inquiries blamed "pilot error," a 2013 independent commission found "persuasive evidence" that the aircraft was subjected to an attack or threat.
The "Lone Pilot" Theory
One prominent theory alleges that Jan van Risseghem, a Belgian-British mercenary pilot flying a Fouga Magister jet for the Katangese rebels, intercepted and shot down Hammarskjöld's plane. This was reportedly witnessed by locals on the ground whose testimonies were ignored by initial colonial authorities.
Intelligence Involvement
The 1998 South African Truth and Reconciliation Commission revealed documents outlining "Operation Celeste," a purported plot by the South African Institute for Maritime Research (SAIMR)—allegedly acting with CIA and MI6 support—to "remove" Hammarskjöld. The UN officially reopened the investigation in 2017 due to the discovery of new declassified information.