A total of 950 miners were stranded underground in a South African gold mine on Thursday after a power cut caused by a storm, said the company owning the mine, saying they “seemed ” in good health.

“Last night, there was a storm in the Free State Province (center) that caused a power outage in the mine, so we could not get back to the surface of the night workers this morning.” said James Wellsted, spokesperson for Sibanye-Stillwater, interviewed on the eNCA television channel.

“There are still 950 miners that need to be brought to the surface” of the Beatrix mine near the town of Welkom, he said, adding that 64 were back in the open.

The miners still underground are stuck at about 1,000 meters deep.

“All employees seem to be well,” said AFP spokesman, adding that food and water were being transported to minors.

The mine generators that are supposed to take over in the event of a power outage do not work, Mr. Wellsted acknowledged.

The Miners’ Trade Union Association (AMCU) denounced “the lack of relief plans for the mine in terms of alternative sources of electricity” and spoke of a “very serious incident in view of the high number” of minors blocked.

Mine accidents are common in South Africa, which has the deepest mines in the world. In 2015, 77 people died in the mines, according to the South African Chamber of Mines.