On September 28, 1970, Egyptian President Gamal Abdel Nasser had just concluded a high tension Arab Summit in Cairo aimed at resolving the "Black September" conflict between Jordan and the PLO. On September 27, Jordan and the PLO signed an accord which essentially treated them as equal parties to the dispute. Nasser spent the morning of the 28th seeing his Arab VIP guests off at Cairo airport. Soon after leaving, he suffered a massive heart attack. He was taken ro his home, where he died later that afternoon.
Though only 52, Nasser was a heavy chain smoker and a diabetic with a family history of heart disease, and the stress of Black September and the Cairo Summit had taken their toll.
The juxtaposition of Nasser's death and the September crisis (which had included threats of US, and Israeli intervention in Jordan and Soviet intervention in Syria) led to shock throughout the region and an outpouring of grief in Egypt. Five million people attended the funeral.