Rescuers recovered eight bodies and continued to search for another missing worker on Thursday after a fire and rock-fall at a Harmony Gold mine near Johannesburg, the worst accident in South Africa's mines in nearly five years.
Mineral Resources Minister Susan Shabangu ordered an investigation into the incident at the Doornkop mine, 30 km west (20 miles) of the city, after initial reports that the fire was triggered by a small earthquake on Tuesday evening.
It is the most serious accident in South Africa's mines since nine workers died in a rock fall at a platinum mine in July 2009. Shares in Harmony, South Africa's third-largest bullion producer, fell 3 percent at the start of trade.
Rescue teams battled through smoke and debris nearly a mile underground on Wednesday to reach eight other miners who had managed to flee to a refuge bay equipped with a telephone and other survival gear. They were brought to the surface unharmed.
South Africa's gold mines are the deepest in the world and were ranked as some of the most dangerous during the apartheid era.
Since the end of white-minority rule in 1994, the government, unions and companies have worked to improve safety, but 112 people were still killed in 2012, the last year for which records are available.
The National Union of Mineworkers (NUM) and Harmony said the fire broke out on Tuesday evening after an earthquake damaged ventilation and water pipes as well as power cables.
Operations have been halted at the mine, which produces nearly 10 percent of Harmony's gold, and a prolonged safety shutdown could hit the company hard.