Bono: Nelson Mandela refused to hate

Watch the rest of CNN's Anderson Cooper's interview with Bono on AC360, Monday at 8 p.m. ET.

(CNN) - Nelson Mandela was a global icon for peace and non-violence, and his memorial service Tuesday is on pace to rival anything seen in decades in terms of size and security presence.

Four United States presidents, 91 heads of state, tens of thousands of South Africans, and celebrities from all over the world are among the throngs of mourners flocking to Johannesburg to bid farewell to Mandela.

There will also be elite military troops, snipers, and security dogs - all there to watch over a stadium meant to hold some 90,000 people, coming to pay their respects and celebrate Mandela's life.

CNN's Anderson Cooper is on the ground in Johannesburg, where he caught up with U2 frontman Bono.