A Grocon company has pleaded guilty to one charge over a Melbourne wall collapse that killed three people.
Grocon Victoria Street, an entity of the building giant, admitted it failed to ensure a safe workplace at the site.
It entered the plea after Magistrate Charles Rozencwajg granted an application to have the matter heard in the Melbourne Magistrates Court, rather than proceeding to a higher jurisdiction.
Grocon Victoria Street now faces a maximum penalty of $305,000, instead of the $1.1 million three Grocon entities could have faced for each charge in the Victorian County Court.
The Victorian WorkCover Authority withdrew two charges each against two other Grocon entities. Mr Rozencwajg said the tragic consequences of the incident meant closure should be a consideration.
"Closure and finality are very important in matters such as this," Mr Rozencwajg said on Thursday.
Teenage siblings Alexander and Bridget Jones, of Melbourne, and Frenchwoman Marie-Faith Fiawoo, 33, were killed when a 15-metre-long section of the brick wall fell onto Swanston Street in the city centre in March last year.
Prosecutor Greg Lyon, for WorkCover, said on Wednesday that by attaching an advertising hoarding to the wall, the company had increased the risk it would collapse but did not cause it.
Grocon Victoria Street, which had control of the site, contracted Aussie Signs Pty Ltd to attach the hoarding but did not ensure it made safety checks nor required it to, Dr Lyon told the court.
The committal hearing for Aussie Signs Pty Ltd, which faces two charges, is continuing while Grocon Victoria Street faces a plea hearing on November 20.
Two witnesses told the committal hearing they looked at the wall after it collapsed and saw that C-shaped wire ties that formed part of the structure were rusted.
Metropolitan Fire Brigade fire investigation and analysis unit manager Inspector Ian Hunter said there were two skins, or layers, of brick with wire connecting the front brick work to the back brick work.
The wire appeared corroded and old, he said.
Damian O'Toole, an MFB officer attached to the fire investigation unit, said the wire ties were rusted through.
"There was no attachment from one skin to another," Mr O'Toole told the Melbourne Magistrates Court.
However, it would not have been possible to tell the wire ties were rusted while the wall was intact, the court heard.
Speaking outside court, CFMEU construction national secretary Dave Noonan said any penalty handed to Grocon will be only a slap on the wrist which would mean nothing to the multi-national corporation.