By Associated PressJOHANNESBURG: A head-on collision between a truck and a bus ferrying workers to a mine in South Africa’s northern Limpopo province left 20 people dead, authorities said Monday. The workers were reportedly going to work on an underground project at a mine owned by mining giant De Beers. Traffic officials were still on the scene of the accident on Monday to investigate the cause. JOHANNESBURG: A head-on collision between a truck and a bus ferrying workers to a mine in South Africa’s northern Limpopo province left 20 people dead, authorities said Monday. Traffic officials were still on the scene of the accident on Monday to investigate the cause.