How many military heads of state died in power in Nigeria?

Analyze the question: We need to count the Nigerian military heads of state who died while still in office.

Recall the military heads of state:

1. Gen. Aguiyi-Ironsi (1966–1966): killed in the July 1966 counter-coup, died in power
2. Gen. Yakubu Gowon (1966–1975): overthrown, survived
3. Gen. Murtala Mohammed (1975–1976): assassinated in the Dimka coup attempt, died in power
4. Gen. Olusegun Obasanjo (1976–1979): handed over to civilians, survived
5. Gen. Muhammadu Buhari (1983–1985): overthrown, survived
6. Gen. Ibrahim Babangida (1985–1993): stepped aside, survived
7. Gen. Sani Abacha (1993–1998): died suddenly in June 1998, died in power
8. Gen. Abdulsalami Abubakar (1998–1999): handed over to civilians, survived

Count: Ironsi, Murtala Mohammed, and Abacha = 3.

(Note: Ernest Shonekan was a civilian head of the Interim National Government, and he is not counted.)

Tip: Remember the trio "I-M-A": Ironsi, Murtala, Abacha. These are the three who died in office, and the others left by coup or handover.