Almost 90 people were rescued while three are still unaccounted for after a building collapsed above a gold mine in South Africa on Friday, a spokesman for the Association of Mineworkers and Construction Union revealed.

The collapse at the Makonjwaan Gold Mine's main entrance trapped 87 workers underground, all of whom were rescued, Vantage Goldfields said in a statement. However, three workers still remain missing. They were working above ground at the time of the collapse and became trapped in the building, according to the Associated Press.

No fatalities were reported, and those rescued didn't suffer any serious injuries, paramedics at the scene revealed. Those who were injured were taken to a local hospital for treatment.

"As we speak they might already all be out. Most have been evacuated," said Mike McChesney, chief executive of the small gold producer, according to Reuters.

The cause of the collapse remains unverified, but for the time being, it's believed that it was caused by sinkhole.

South Africa is rich in resources, possessing several gold, platinum, diamond and coal mines, reported Sky News. However, those mines also rank among the deepest and most dangerous in the world. However fatalities in the industry have become increasingly less common due to improved safety practices and a reduction in the labor force as production declines. For example, 77 workers were killed in mining accidents last year, compared to the 84 from before.

This is the second mining accident to occur in South Africa in recent weeks. Four miners were killed in an underground fire in a platinum mine near Johannesburg last month.