The Johannesburg-based platinum miner said in a statement that 86 workers were involved in the incident at its No. 11 shaft and 75 injured workers had been admitted at four hospitals in the area.
The company said all mining operations at the sprawling Rustenburg complex in South Africa's North West province had been suspended on Tuesday.
"Today is the darkest day in the history of Impala and our hearts are heavy for the lives lost and the individuals affected by this devastating incident," CEO Nico Muller said in the statement.
Impala is among South Africa platinum producers that operate some of the deepest and oldest mining shafts in the world.
The suspension could be extended to Wednesday to allow the company to "mourn and heal emotionally", a company spokesperson said.
(Reporting by Felix Njini; Editing by Kim Coghill and Jamie Freed)