Feb. 6 (Bloomberg) -- Harmony Gold Mining Co. said eight workers are dead and one missing after a rockfall triggered a blaze more than a mile underground at its Doornkop site in South Africa’s worst gold company accident for 5 1/2 years.
“The seismic event created the fall of ground, which in turn damaged the cable, which sparked the fire,” Chief Executive Officer Graham Briggs said in a telephone interview. “The fire is what’s the dangerous thing because it contaminates the atmosphere: gases and smoke.”
South Africa, once the largest gold producer, has some of the deepest mines as aging deposits prompt companies to dig further for ore. The Doornkop incident is the worst in the local industry since nine died when the cable of a shaft elevator snapped in May 2008 at Gold Fields Ltd.’s South Deep mine.
Search and rescue and deep-level firefighting teams were deployed at Doornkop at about 6 p.m. on Feb. 4 after the fire broke out 1,733 meters (5,700 feet) below the surface, Harmony said. About 130 miners were underground at the time, with 35 in the immediate vicinity of the fire, 18 of whom were able to get immediately, Briggs said. Eight miners were found in an underground refuge chamber and brought out unharmed yesterday.
“We have a group of people basically who didn’t get to a refuge chamber, and we don’t know exactly why,” Briggs said. “We are still searching for the last person; we believe we’ve got some good information on location, so that’s where we’re focusing on.”
It’s the most Harmony employees to die in an incident in the company’s history. At least 82 illegal miners died at a disused mineshaft owned by Harmony, South Africa’s third-largest gold producer, in Free State province in 2009.
“We pass our deepest condolences to the families of the deceased,” Erick Gcilitshana, the National Union of Mineworkers’ health and safety secretary, said in a statement. “One death is one death too many.”
Once the last missing Harmony worker is found, the search and rescue team will need to make sure the fire has been extinguished before an inspection can start, South Africa’s Department of Mineral Resources said. The fire may still be causing the release of gases by the end of the week, delaying the inspection, which itself will take “quite a few days,” Briggs said.
Harmony fell 3.9 percent to 29.77 rand by the close in Johannesburg, the most in seven weeks. The FTSE/JSE Africa Gold Mining Index was 0.5 percent lower.
Mines Minister Susan Shabangu promised “thorough investigations” of the incident as she spoke at a press conference at the mine, along with Harmony Chairman Patrice Motsepe.
Doornkop, about 30 kilometers (19 miles) from Johannesburg, produced 3,631 kilograms of gold in 2013, according to Harmony’s website. The single-shaft mine at a depth of just under 2,000 meters accounts for about 10 percent of the company’s South African production. There were two fatalities at Doornkop in 2012 and none last year.
A tremor with a magnitude of 2.4 caused the initial rock fall, according to the National Union of Mineworkers, which said ventilation and water pipes were also affected. There were 112 deaths in the country’s mining industry in 2012, according to the Chamber of Mines.
While Johannesburg flourished after the discovery of gold in 1886, the stress that mining has placed on underground rock formations has increased seismic activity.
“There’s nothing about a seismic event that one can really do,” Franz Stehring, head of mining at the union Uasa, said in a phone interview. Investigators will be checking whether the workers had their rescue packs, which supply enough oxygen for 60 minutes, whether the rescue bays work and whether the workers knew where to find the refuges, he said.
South Africa’s deadliest mining incident was in 1960, when 437 miners were killed at the Coalbrook North Colliery after being trapped by a rock fall, according to the website of state-owned power utility Eskom Holdings SOC Ltd. In 1986, an underground fire killed 177 miners at the country’s Kinross gold mine.