More than 3,000 mineworkers spent more than 11 hours trapped underground in the Elandsrand mine, near Carletonville, about 110 km west of Johannesburg on Wednesday.
Harmony Gold spokeswoman Amelia Soares said the incident happened after a falling pipe column cut the power to the lift used to hoist them to the surface.
"Nobody was injured, but there was extensive damage to the steel work and electrical feeder cords," she added.
Workers above ground were trying to reconfigure a second cage -- usually used to carry waste -- to rescue the trapped workers, according to a report by South African Press Association.
While it was expected the lift would be working in two hours, the rescue operation itself would "take quite a while" as the cage could bring only 300 workers to the surface every half hour, she said.
Mine management was in constant contact with the workers, who had access to water and adequate ventilation, said Soares.
Their families were being kept informed of developments via a special control room at the mine.
The National Union of Mineworkers (NUM) said the mine workers had been trapped since 10 a.m. It was only after 9 p.m. that news of the incident surfaced.
There was no emergency exit in the shaft, which had "not been maintained for ages," NUM spokesman Lesiba Seshoka charged in a statement issued on Wednesday night.
However, Soares said there were other outlets for workers, some of whom were making their way to shafts in an adjacent AngloAshanti mine.
She said 3200 miners were trapped when a 15 meter section of a compressed pipe column broke -- because of fatigue -- just below the shaft surface bank and fell to the bottom of the shaft used to carry men and materials.
Explaining why so many people were trapped underground, Soares said the company had purchased an old mine and extended the shaft downwards.
This meant there were not only people working on the old mine, but workers busy on the new "project" below it, and which was scheduled for commissioning in two years.
(Xinhua News Agency October 4, 2007)