The Association of Mineworkers and Construction Union (AMCU) says it is saddened by a "tragic start to 2020" as three mine workers died while on duty last week.
According to the union, a locomotive driver was injured in a mud rush at Harmony Gold.
"Reportedly, the worker went to inspect the box chute, which conveys ore into locomotive carriers, and for some reason yet unknown the box opened and overwhelmed him with collected ore, killing him. The AMCU comrade was from Lesotho and he leaves behind a wife and four children."
A few days later, another mine worker had been absent from night shift and was later found dead underground at the Phakisa mine near Odendaalsrus in the Free State.
"We await the conclusion of the investigation," the union said.
A third mine worker died that same week at Sibanye-Stillwater’s Bambanani Shaft near Rustenburg, according to AMCU.
"A rock drill operator was tragically killed in a fall-of-ground incident. He was a Mozambican national.
"Investigations are underway."
AMCU lamented the number of workers who have died at Harmony Gold who, it said, had suffered ten fatalities in 2019.
"The union has been consistently calling for amendments to the Mine Health and Safety Act. But, yet again we see another breadwinner killed," AMCU said.