An employee measures a rough diamond at the polishing affiliate of Russian diamond producer Alrosa in Moscow. A wall collapsed at Petra Diamonds' Cullinan mine, east of Pretoria following a thunderstorm, the company said on Wednesday.

RUSTENBURG - A wall collapsed at Petra Diamonds' Cullinan mine, east of  Pretoria following a thunderstorm, the company said on Wednesday.

A sidewall of the open pit collapsed on Saturday and on Monday, no one was injured in the incident, the company said in a statement.

Mining in the open pit at Cullinan was discontinued more than 50 years ago and all current mining operations are underground. 

"The scaling was along geological structures with approximately 3 million tonnes of material falling into the open pit. The scaling resulted in a large plume of dust being generated, having some effect on the local community and entering the underground areas " the company said.

"As a precautionary measure, all employees were evacuated, while an underground team of ventilation specialists and proto team members carried out an underground inspection and declared the mine safe, with the result that underground mining resumed later on the evening of Monday 28 October. Community members were also engaged to assess the impact.

"Following this incident, there has been thorough engagement with the department of mineral resources, the labour unions and the local community, with a number of actions agreed upon. The operation is being disrupted for approximately one day in order to give management the opportunity to thoroughly inspect the underground workings for any anomalies and to complete a risk assessment before allowing operations to continue," it said.


"The nearest Cullinan community is on the southeastern corner of the pit and ongoing monitoring of the pit walls show no unusual movement, other than in the south-west corner where ongoing scaling is evident. As a result, we do not foresee any risk to the larger community. Petra's dedicated community response team is in direct contact with the community to assist with any concerns and a public meeting will be scheduled later this week to provide further information on the matter."

CEO Richard Duffy said the company would take necessary steps to understand the incident and any impact on future pit stability.

"We will take whatever steps are necessary, including the engagement of external technical specialists if required, to better understand this incident and any impact on future pit stability. The safety of our employees and surrounding communities continue to remain our key focus. Our meetings with our partners in government, labour unions and the community earlier today were very constructive and their valued input is appreciated."

- African News Agency (ANA)