South African rescuers freed eight miners one mile underground on Wednesday after a seismically-triggered fire and rock-fall at a Harmony Gold Corp. mine near Johannesburg; nine others remain missing.

Rescue teams fought smoke and debris to reach the eight, who managed to ascend to a refuge bay with a telephone and survival equipment including food, water and breathing devices; all normal mine site operations have been suspended.

Chief executive Graham Briggs skipped Mining Indaba, Africa’s top mining event, to personally oversee the rescue effort 20 miles west of Johannesburg. The Doornkop project lies within the west rand, a rich but extremely deep gold seam.

“The fire occurred in a stope adjacent to 192 level haulage (1,733 meters underground) at 6 p.m on Tuesday,” said Harmony spokesman James Duncan as quoted by Reuters News.

National Union of Mineworkers (NUM) officials reported the fire erupted after a small earthquake damaged ventilation and water pipes along with power cables. “The fire underground is still burning,” they said in a statement quoted by Reuters.

South Africa’s gold mines have been ranked among the world’s deepest and most treacherous – especially through decades of white minority rule ending in 1994.

But while the government, unions and companies have worked to improve safety, troubles persist. In 2012, most notably, 112 men perished in mine accidents; then three years earlier, more than 80 died after an underground fire at a Harmony mine.

Sub-Saharan Africa’s No. 1 economy is also the continent’s leading gold supplier, followed by Ghana and Mali. South Africa is also the world’s top producer of platinum, a precious metal.