Gold Fields Ltd., one of South Africa's largest gold producers, closed down its KDC mine Sunday after five employees died due to an overnight fire that broke out.

Gold Fields reports that fire fighters are working to control the fire, that also led to 14 hospitalized workers.

KDC was responsible for producing 1.1 million ounces of gold by the end of December 2011.

Gold Field managers shut the mine down completely and are currently working with the Department of Mineral Resources to figure out the cause of the fire.

According to South Africa's National Union of Mineworkers, the five employees who died were reported to have inhaled too much smoke.

"We strongly condemn the company for sending workers on overtime night shift when there is no ventilation," said Frans Baleni to foxbusiness.com, the NUM General Secretary.

The deaths come at a time when the South African mines department has recently scrutinized companies to abide by safety rules.  Similar pressure was placed on the platinum industry just last year.

"The loss of five miners at one go is a sign of serious lack of care especially when there is lip service from the industry that says one life is a life too many,"Mr. Baleni said.