Stillwater CEO Neal Froneman said he was "deeply saddened and traumatised" to have lost so many mineworkers at the mine's operations.
"In my entire 40-year career in mining, I have never experienced anything like this. I am deeply saddened and traumatised to have lost so many Sibanye-Stillwater family members in this way," Froneman said during a conference call on Monday afternoon.
The aim of the conference call was to address recent safety incidents and other relevant issues.
The death toll at Sibanye-Stillwater's operations this year alone stands at more than 20 - close to half of the fatalities in the entire mining industry.
Froneman said, during the five years prior to 2018, operations have delivered industry reading safety rates.
He said 2017 marked an extensive roll-out of a revised safety strategy early in the year and there was a significant improvement in all safety indicators.
According to Froneman, the country's gold operations experienced no fatalities for four months until early February 2018.
"Whatever we do, it will not bring back those men to their family."
Referring to the May 3 incident where seven workers were killed during a seismic event, he said seismic events were common across the gold fields areas.
"Seismic activity is common across the western gold fields and on average, our Kloof and Driefontein mines experience 640 events of between one and two magnitudes a year, and approximately 84 larger-than-two-magnitude events on average a year."
In a separate incident on June 11, five miners died when they entered a ventilation shaft.
Froneman said photographs revealed that the ventilation shaft had been locked and marked with "no-entry signs" and it was unclear why the miners entered the area.
He said the Department of Minerals and Resources was still investigating the incident.
Sibanye-Stillwater has also appointed an expert in mining safety Cobus de Jager as corporate head of safe.
De Jager boasts more than 40 years of experience in mining safety.
His primary focus will be to fully review the company's safety management systems and processes.
"We are taking structured and well-defined steps to restore our safety performance," Froneman said.