Purim
There is a tale in the Hasidic Chabad movement that supposedly Joseph Stalin died as a result of some metaphysical intervention of the seventh Chabad leader, Rabbi Menachem Mendel Schneerson, during the recitation of a discourse at a public Purim Farbrengen. Stalin was suddenly paralyzed on 1 March 1953, which corresponds to Purim 1953, and died 4 days later. Due to Stalin's death, nationwide pogroms against Jews throughout the Soviet Union were averted, as Stalin's infamous doctors' plot was halted.
Live fire exercise
The Soviet Union, just after Joseph Stalin died in 1954, conducted a live nuclear test, during exercises at the Totskoye range, against soldiers at a distance believed to be safe when in trenches. Any immediate deaths can't be proven today, but Russian human rights activists assert that the long aftermath death toll is in the thousands.