Why did Ghana's economy/empire collapse?

Ghana was combined in the kingdom of Mali in 1240 marking the end of the Ghana Empire. A tradition in historiography maintains that Ghana fell when it was sacked by the Almoravid movement in 1076-77, although Ghanaians resisted attack for a decade. but this interpretation has been questioned.

Capital: Koumbi Saleh

Religion: African traditional religion, Islam

Common languages: Soninke, Malinke, Mande