Final answer:
The exact cause of Sunni Ali's death in 1492 is not documented, and historical accounts do not single out a specific manner of death such as drowning, being sawed in half, or poisoned.
Step-by-step explanation:
The question pertains to the death of Sunni Ali, the founder of the Songhai Empire, rather than the death of Caliph Ali, who was central to the split between Sunni and Shia Islam. Historical records regarding Sunni Ali's death in 1492 are not clear, and there are no widely accepted accounts that detail how he died, whether by drowning, being sawed in half, or poisoned. However, after his death, his son Sonni Baru came to power briefly before being defeated by Muhammad Ture, who then took the throne as Askia Muhammad, also known as Askia the Great. Sunni Ali's reputation varies: while he was criticized by Arabic historians for his actions against Muslim forces and scholars, he is remembered in Songhai oral tradition as a conquering hero and a key figure in the empire's wealth and expansion.