A former Lily Mine manager said the collapse of the mine, which left three workers trapped underground, was an eye-opener on how things should be done better in the future to prevent another catastrophe.
On Thursday, Eben Swanepoel said they had to come with remedial steps after every disaster due to that incident.
Swanepoel was testifying at an inquest hearing, sitting in the Nelspruit Magistrate's Court, which is looking into the collapse of a container into a sinkhole on 5 February 2016.
"We had to revisit everything we had identified to prevent another failure. After every disaster [in future], we must come with remedial steps. When you open any mine with regards to a crown pillar, those steps should be considered," he said.
On Wednesday, one of the witnesses' lawyers, Richard Spoor, said before the mine's collapse, Rudiger Kersten had complied a report where he revealed he was worried about the crown pillar's collapse and proposed it be moved somewhere else.
The container in which Samuel Nyirenda, Pretty Nkambule and Yvonne Mnisi worked in was above the crown pillar.
Testifying on Thursday, Swanepoel said: "All I know is that Kersten raised that in his report because he was doing the calculations. He identified the risk. There was no obligation beyond my view to inspect the crown pillar from time to time.
"Nowhere has anyone identified the crown pillar as the risk. The cause of the collapse was never identified earlier. Kersten only identified the water issue involving a dam, and that was before I joined the mine.
"We protected our employees against any danger that would put their lives at risk. There was no procedure on how to deal with illegal miners. We spent a lot of money beefing up security. "I became aware of illegal mining at levels 8 and 10. I think I was told by one of my colleagues. We pounced on them unannounced. We didn't want zama zamas to know when we were coming to raid them."
He added he was appointed as the mine manager in 2011 and in 2015 he was promoted to general manager.
"Following my promotion, I was also involved in security matters for the company. There was continuous monitoring of mining activities. On the other hand, we observed the crown pillar from a zero point. The distance was about 28m away from the crown pillar. I didn't even see water coming down through the crown pillar.
"Nobody was directly responsible for monitoring the crown pillar. I think the mine captain could have done that. Following the tragedy, we authored a report into the incident," said Swanepoel.
However, magistrate Annemarie van der Merwe asked him why the mine never implemented the report compiled by Kersten.
She told Swanepoel the report had indicated a shift at the entrance of the crown pillar below the container in which the three were working in.
Van der Merwe also told him Kersten had indicated he had a problem with infrastructure on top of the backfill.
"He mentioned that the possibility of monitoring the crown pillar with technology would be investigated. In hindsight, the monitoring of the crown pillar was not sufficient. Why did Kersten persist on raising the issue of moving the portal to another place?" she asked.
The inquest aims to determine who was responsible for the tragic incident that left Nkambule, Mnisi and Nyirenda trapped underground.
They are presumed dead.