PHOTOGRAPHS of the deadly wall that collapsed riddled with cracks have been declared a 'shocking revelation', with calls for Worksafe to explain the inspection oversight.
Photographs obtained by the Herald Sun and taken just four months ago are now expected to form a crucial part of investigations into last week's tragedy.
Engineering experts have said the "significant" cracking would have made the wall unable to resist Thursday's strong winds.
The photographs taken on December 12 last year are the only images in the public domain that shows the condition of the wall before its collapse.
Opposition WorkCover spokesman Robin Scott said the photographs were a shocking revelation.
"These are a shocking revelation about the tragic loss of three vibrant young lives," he said this morning.
"The evidence from the engineers states they what they believe was the cause of the accident."
Mr Scott said WorkSafe needed to explain what it did when it inspected the site in 2011.
Cracks are clearly visible in the wall. Picture: Jes Richardson
"What we need to know is why these problems were not picked up earlier and WorkSafe should give a clear explanation to the public," he said.
"The public deserve to know."
Montmorency community to farewell Alexander and Bridget Jones
The tragedy claimed the lives of three pedestrians on Swanston St - Melbourne siblings Bridget and Alexander Jones and French woman Dr Marie-Faith Fiawoo.
Grocon knocked down the remaining sections of the wall under instruction from authorities in the hours after the incident.
WorkSafe also confirmed it had visited the Grocon building site in 2011 to monitor work practices, but could not say whether the wall was inspected.
Dr Con Adam, senior research fellow in the school of civil engineering at Monash University, said the cracks caused the wall's collapse.
Wall collapse victims Bridget and Alexander Jones and French woman Dr Marie-Faith Fiawoo.
"That picture tells us a lot about the wall. The wall as a whole was under sheer failure, this renders the wall unable to resist wind loads," he said.
"The wall, if it was designed properly should flex with the wind and go back without collapsing.
"If there is a crack in the bottom of the wall it just couldn't resist the wind load. That crack at the base of the wall was the weakest point."
Jes Richardson, 25, a self-described "urban explorer", was taking pictures of graffiti on December 12 last year when she captured the image of the graffitied Grocon wall.
She said a bluestone wall at the other end of the site near Bouverie St was propped up with metal beams.
"If that fell, it would fall on to the footpath," she said.
The Herald Sun understands investigations have now turned to the brickwork and foundations of the wall, after a wooden hoarding acting like a sail was initially blamed for the collapse.
Ms Richardson said she hoped the photographs would help the investigation into the fatal collapse.
Photographs of the wall taken four months ago reveal cracks in the lower bricks and show that the hoarding is higher than the wall. Picture: Jes Richardson
The Bureau of Meteorology confirmed that westerly winds of 102km/h were recorded at the St Kilda beacon, the nearest accurate weather station, at 2.59pm last Thursday, moments before the wall fell.
Richard Eckhaus, chairman of the Structural College of Engineers Australia, said the crack at the base of the vertical part of the brickwork, known as a pier, was a serious problem.
"There is a significant crack in the engaged pier; there's also a minor crack below," he said. "That tells you the wall is not in a good condition."
He said the wooden hoarding should have been checked by an engineer before it was approved.
A makeshift attempt had also been made to shore up a wooden section of the advertising board.
Vegetation had also grown through parts of the wall and the concrete foundation had been chipped.
WorkSafe's acting general manager of health and safety, Shane Gillard, said the authority attended the site on October 12, 2011.
The scene of the Swanston St wall collapse. Picture: Tim Carrafa
But he could not say if the wall was inspected.
"The request related to concerns over the safety of workers who were using A-frame ladders to erect the hoarding on the site and the lack of a pedestrian management system while the work was being carried out," he said.
"An inspector visited the site and confirmed that the employer had in place appropriate health and safety measures to protect its employees and the public while the work was being carried out."
