Short answers, pulled from the story.
Hafizullah Amin was the leader of Afghanistan who was deposed by Nur Muhammad Taraki in September 1979. He died during Operation Storm-333 on the 27th of December 1979 when Soviet forces raided Tajbeg Palace.
Operation Storm-333 began around seven p.m. on the 27th of December 1979 and lasted approximately forty minutes. The raid targeted Tajbeg Palace where Hafizullah Amin resided with his family.
The core assault team included twenty-five men from the Grom unit of Alpha Group, thirty operators from the Zenit KGB group, eighty-seven troops from the 345th Independent Guards Airborne Regiment, and five hundred and twenty soldiers from the Muslim Battalion. These forces were joined by Sayed Mohammad Gulabzoy to lead them toward Tajbeg Palace.
Thirty-four other Afghans including thirty personal guards perished in the fighting along with three hundred soldiers killed and another one hundred fifty captured. Five officers of the KGB special forces died during the assault while seven troops from the Muslim Battalion were also killed.
Soviet leadership viewed Hafizullah Amin as a threat after he shifted power within the People's Democratic Party of Afghanistan following Taraki's deposition. Documents released after the dissolution of the Soviet Union revealed that Soviet leadership believed Amin had secret contacts within the American embassy despite allegations being widely discredited.