Johannesburg | An elevator suddenly dropped around 200 metres (656 feet) while carrying workers to the surface in a platinum mine in South Africa, killing 11 and injuring 75, the mine operator said Tuesday.

It happened Monday evening at the end of the workers' shift at a mine in the northern city of Rustenburg. The injured workers were hospitalized.

Impala Platinum Holdings (Implats) CEO Nico Muller said in a statement it was “the darkest day in the history of Implats.” It said an investigation had already begun into what caused the elevator to drop and the mine had suspended all operations on Tuesday.

All 86 mine workers killed or injured were in the elevator, Implats spokesperson Johan Theron said. Some of the injured had “serious compact fractures,” he said. Theron said the elevator dropped approximately 200 metres down the shaft, although that was only an early estimate. He said it was a highly unusual accident.

South Africa is the world's largest producer of platinum.

The country had 49 fatalities from all mining accidents in 2022, a decrease from 74 the year before. Deaths from South African mining accidents have steadily decreased in the last two decades from nearly 300 in the year 2000, according to South African government figures.