Shavuos & The Baal Shem Tov's Shul
The Sudilkover Rebbe noted that on Shavuos in 1939 [May 24, 1939] the Communists permanently closed down and locked the Baal Shem Tov's shul in Mezhibuz. This occurred exactly 279 years to the day after the Baal Shem Tov passed away. Interestingly, the Rebbe explained that 279 is the gematria of ויסגר ("and it will be closed").
On Shavuos in 1942 [May 22, 1942], the Nazis along with help from members of the Ukrainian militia burned down the Baal Shem Tov's shul. This occurred exactly 282 years to the day after the Baal Shem Tov passed away. To this, the Rebbe explained that 282 is the gematria of הבערה (burning).