Johannesburg - Impala Platinum (Implats) shares fell more than R30 yesterday after it disclosed it was halting production at the No 11 Shaft of its mine complex near Rustenburg to beef up underground safety.
Implats said it had decided on this action following the deaths of four miners in three separate accidents last month.
The shaft, which contributes 10 percent of Implats' annual production of 1 million ounces of platinum and platinum group metals, will not have any output of ore for the rest of the week.
Gert Ackerman, the operations executive of Implats, said the cost of lost production would be more than R20 million.
"But you cannot put a price on safety," Ackerman stressed.
He said Implats had recorded 12 underground fatalities this year. The four miners who died at No 11 Shaft in May - two were killed on Friday - were all victims of falls of ground.
Falls of ground is the mining term for rocks falling from the roof (hanging wall) or side walls. It can be the result of a rock bursting under pressure, but is usually caused by failure in the support props, packs or a lack of hazard awareness.
Falls of ground are the main safety concern of the local mining industry as they result in more deaths than any other underground accidents.
Ackerman said: "The National Union of Mineworkers is very understanding and agree with the action we have taken."
He said the 2 000 underground workers at No 11 Shaft were still reporting to their work stations, but were not involved in production. Instead, they were doing routine cleaning and maintenance duties while being reappraised of the procedures essential for safe underground labour.
The men will receive their normal pay, but will not get any production bonuses.
Implats stock closed R30.60 lower on the JSE Securities Exchange yesterday at R609.79.