RICHARDS BAY, South Africa—Last May, three men strode into a suburban street and sprayed gunfire into a car, killing mining executive Nico Swart on his way to work.
Mr. Swart, 47 years old, had been a general manager at Richards Bay Minerals , or RBM, which is majority owned by global mining giant Rio Tinto PLC. His murder, which is still under investigation, marked another grim flashpoint in the decline of South Africa’s signature industry.
