Impala Platinum halts some South African mines after 11 workers died

JOHANNESBURG, Nov 28 (Reuters) - Impala Platinum (IMPJ.J) on Tuesday temporarily halted operations at its Rustenburg mining complex in South Africa after 11 workers died and 75 were injured in what the CEO said was "the darkest day" in the company's history.
Impala said in a statement that workers were being brought to the surface at the end of their shift on Monday when the conveyance system that carries workers up and down an underground shaft 1,000 meters (3,281 ft) deep started a rapid descent.
The Johannesburg-based platinum miner said 86 workers were involved in the incident at its No. 11 shaft. The injured were admitted to four hospitals in the area, and a company spokesperson said medical physicians had classified 14 workers in the hospital as "high priority".
"Today is the darkest day in the history of Impala and our hearts are heavy for the lives lost and the individuals affected by this devastating incident," CEO Nico Muller said in a statement.
Muller said at a media briefing the conveyance system had been tested prior to being used, and indications were the core systems were active and operational.
"An investigation has to lead us to understand how, with a positive signal on the safety systems, you still have an incident where a conveyance starts gravitating to the bottom and then gets into uncontrollable descent," Muller said.
All mining operations at the Rustenburg complex in South Africa's North West province were suspended on Tuesday. The halt could be extended to Wednesday to allow the company to "mourn and heal emotionally", Impala spokesperson Johan Theron said.
He also said investigations into the cause of the accident had begun.
Impala's shares in Johannesburg were down 8% at 1335 GMT.
South Africa has some of the world's deepest, oldest and most costly platinum and gold mining shafts.
The deaths at Rustenburg add to the 41 fatalities that had been recorded in South Africa's mining industry this year so far.
Last year 49 workers died in South Africa's mines, which was the lowest number of fatalities to date, the industry lobby group Minerals Council South Africa said.
Spokesperson Theron said he could not be precise about the impact of the stoppage on Impala's metals output.
"It's impossible to quantify the impact on production save to say No. 11 shaft on its own is a very large complex and contributes roughly 15% of Impala Rustenburg's production," Theron said.
"To the extent that it's stopped for any length of time, it will have a corresponding impact on the entire company."
The affected shaft could take longer to re-open as authorities and the company need to conduct thorough investigations, Mandi Dungwa, an analyst at Camissa Asset Management, said.
"This looks like a mechanical failure so it may take time for the investigations to be concluded," Dungwa told Reuters. "However long it's going to be closed, it will have an impact on production, and on costs."
Reporting by Felix Njini and Nelson Banya; Editing by Kim Coghill, Jamie Freed, Louise Heavens, Barbara Lewis and Jan Harvey