"What is clear here is that we have to go deeper into this issue and find out how we ended up in this situation. Find out who was responsible for security, was there enough personnel, what was the role of the stakeholders.
"Did the stakeholders play their roles, and if not why not?" said Nxesi.
The minister said theterms of reference had been sent to the Department of Justice for a legal opinion before moving forward and appointing a judge.
The PSL appointed Vincent Maleka SC to conduct an investigation into the disaster, but Moemi said it had nothing to do with the ministry's inquiry.
"The PSL investigation is their business and it has nothing to do with us," the director-general said.