The single cause of this accident was a part of the cargo it carried.
Of significance is the quote from the accident investigation report:
"The Cargo Group examined shipping invoices for the cargo on board the
aircraft, and at least three shipments of lithium batteries which should have been declared as hazardous materials were identified in the pallets at positions 4 and 5. There were no declared shipments of hazardous materials on board the accident flight. "
If they should have been declared as hazardous, then why were they not so declared.
Given the lesson in the Valuejet flight 592 this is an accident that should not have happened.