January 3, 1961

1961Cold War: After a series of economic retaliations against one another, the United States severs diplomatic relations with Cuba.^[†]

The Cold War was a period of global geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 until the dissolution of the Soviet Union in 1991. The term cold war is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, embargoes, and sports diplomacy.

1961The SL-1 nuclear reactor, near Idaho Falls, Idaho, is destroyed by a steam explosion in the only reactor incident in the United States to cause immediate fatalities.^[†]

Stationary Low-Power Reactor Number One, also known as SL-1, initially the Argonne Low Power Reactor (ALPR), was a United States Army experimental nuclear reactor in the western United States at the National Reactor Testing Station (NRTS) in Idaho about forty miles (65 km) west of Idaho Falls, now the Idaho National Laboratory. On January 3, 1961, at 9:01 pm MST, an operator fully pulled out the reactor's central control rod, causing the reactor to go from fully shut down to prompt critical. The intense heat from the nuclear reaction expanded the water inside the reactor core, producing extreme water hammer and causing water, steam, reactor components, debris, and fuel to vent from the top of the reactor where the three operators were working. As the water struck the top of the reactor vessel, it propelled the entire reactor vessel to the ceiling of the reactor room where it struck the overhead crane. A supervisor who had been on top of the reactor lid was impaled by an expelled control rod shield plug and pinned to the ceiling. The release of materials hit the two other operators, mortally injuring them as well. The reactor vessel then fell down to its original position.

1961A protest by agricultural workers in Baixa de Cassanje, Portuguese Angola, turns into a revolt, opening the Angolan War of Independence, the first of the Portuguese Colonial Wars.^[†]

Baixa de Cassanje, also called Baixa de Kassanje is a non-sovereign kingdom in Angola. Kambamba Kulaxingo was its king until his death in 2006. Presently, Dianhenga Aspirante Mjinji Kulaxingo serves as the king.

1961Aero Flight 311 crashes into the forest in Kvevlax, Finland, killing 25 people.^[†]

Aero Flight 311, often referred to as the Kvevlax air disaster, was a scheduled domestic passenger flight operated by Aero O/Y between Kronoby and Vaasa in Finland. The aircraft, a Douglas DC-3, crashed in the municipality Kvevlax, nowadays part of Korsholm on 3 January 1961, killing all twenty-five people on board. The disaster remains the deadliest aviation accident in Finnish history. The investigation revealed that both pilots were intoxicated and should not have been flying.