A Perth building company is being prosecuted after a German backpacker plunged 13 storeys to her death through an open shaft at an apartment project.
Labour hire worker Marianka Heumann, 27, died at the Hanssen-run Concerto construction site on Adelaide Terrace, East Perth in October 2016.
WorkSafe said on Thursday it had not laid any charges in relation to her death.
But the investigation revealed Hanssen had repeatedly breached occupational safety regulations at the site by failing to cover holes or openings in concrete floors with mesh during construction.
After Ms Heumann's death, Hanssen managing director Gerry Hanssen told ABC radio she had taken her safety harness off only moments before.
Mr Hanssen also sent a letter to Ms Heumann's family saying a monk had gone to the site to bless her spirit, and when asked what she would say if she could talk, the monk replied: "I am sorry for letting you down to my mum, dad, family, friends and workmates".
The CFMEU was outraged, saying the bizarre letter blamed her for her death.
Hanssen was last month fined $47,500 after a nearly four-tonne concrete tilt-up panel fell from the 34-storey Vue Tower project on Adelaide Terrace into a car park, crushing two vehicles.
The incident again involved labour hire workers.
In August, the state government announced it would introduce industrial manslaughter legislation and add 21 more WorkSafe inspectors.