WorkSafe accuses South32 of negligence in Simon Mukwarami’s death at Worsley Alumina: leaked document

A much-loved father died at a Western Australian alumina refinery because there were “no controls” in place “to prevent a fall”, a leaked document from the State’s safety regulator has revealed.

Simon Mukwarami was working as a boilermaker on a digester at South32’s Worsley Alumina refinery near Collie when he fell through a grid mesh walkway to his death during the early hours of March 14.

A WorkSafe notice provided to South32 following the fatality flagged significant issues on site.

“I observed that sections of grid mesh had been removed from the floor and no controls were in place to prevent a fall, including the absence of fall-arrest equipment,” the safety inspector stated.

“I also observed scaffolding with what appeared to be temporary guardrails installed without post supports at the correct span intervals.

“Based on these observations, I have formed the reasonable belief that the person with management or control of the workplace has not provided adequate protection against the risk of workers falling.”

A South32 spokesman in response to the scathing WorkSafe assessment said the company “takes the safety of its workforce seriously”.

“[South32] is cooperating with the authorities on their ongoing investigations into the fatality at Worsley, and continues to review its existing controls and established safety processes,” he said.

“Once again, we express our sincere condolences to the family, friends, and colleagues of Simon Mukwarami.”

The WorkSafe inspector in his notice also referenced “previous serious incidents at this site involving workers falling”, which he said “may indicate a risk of the offence being repeated”.

In September 2014, 66-year-old Colin Whitton died at Worsley after falling down an elevator shaft near a conveyor belt.

WorkSafe is yet to disclose any planned prosecutions related to Mr Mukwarami’s death, which was the first fatality at a WA mine site or refinery since August 2025.

The safety regulator gave South32’s Worsley Alumina two of the seven awards on offer at its annual “safety excellence” awards in October. This was the most of any mining or refining operation.

Miner’s Promise — a Perth-based charity that provides support for bereaved mining and resources families — has called for donations for Mr Mukwarami’s family.

“Simon was 47 years old, loving husband to Patience and father to Natasha,” the charity stated.

“They had been building a life in Australia, full of hope and opportunity, shaping the future they had dreamed of together.”

Mr Mukwarami, who resided in the Perth suburb of Treeby, was remembered fondly on social media by dozens of his former colleagues at Worsley and Rio Tinto’s Argyle diamond mine.

“Rest in peace Simon, the world has lost a genuinely good soul. Thanks for the banter and laughs that made screen panels fun. I can’t believe it. This should never happen,” one post read.