"My son died for no reason, he didn't deserve to die like that."

Eyes bloodshot, Xiancong Wu's face is drained of colour. His wife, Guojuan, is slumped sobbing by his side, overcome by grief.

Just a few weeks have passed since their 20-year-old son, Dillon Wu, died while working at a Melbourne factory. He was found unconscious and alone at the bottom of a large metal tanker, overcome by fumes.

Dillon Wu was 20 years old when he died on his second week working as an apprentice. ( Supplied )

Dillon had just started his dream job — a prestigious metal engineering apprenticeship with the training arm of The Australian Industry Group, one of the country's most powerful business groups.

"At the start of this job he was like, 'I'm going to do at least two years until I have enough money to buy my own house and everything, so my life can go a better way,'" said Dillon's sister, Xinlei Wu.

"Now he's not going to do any of those."

Now, Ai Group has been accused of sending him to work in a factory it knew was riddled with deadly safety hazards.

The lobby group, which represents some of Australia's biggest companies, was Dillon's direct employer. But his practical training began at Marshall Lethlean — a company in Melbourne's outer east that builds tanker trailers for transporting petrol, milk, chemicals and gas.

Got a confidential news tip? Email ABC Investigations at investigations@abc.net.au For more sensitive information: Text message using the Signal phone app +61 436 369 072 No system is 100 per cent secure, but the Signal app uses end-to-end encryption and can protect your identity. Please read the terms and conditions.

ABC Investigations has obtained a copy of a safety audit Ai Group carried out at Marshall Lethlean's factory as part of a WorkSafe Victoria initiative in August, a month before Dillon was deployed.

The report catalogued a litany of serious hazards, including the factory's lack of procedures for staff working in confined spaces, which it categorised under "High/Significant Risk, Almost Certain likelihood, Serious consequence".

Despite Ai Group identifying 11 high-priority safety hazards in a report delivered to Marshall Lethlean on August 24, its training arm sent Dillon Wu to begin his apprenticeship at the factory a month later.

Dillon Wu was found alone and unconscious inside this tank by his co-workers at Marshall Lethlean. ( Supplied )

But Ai Group's chief executive, Innes Willox, defended his organisation and said the safety hazards outlined in the report would be common in most workplaces.

"These were issues that were identified more broadly and were not found or seen to be insurmountable, but needed work done and that would be done over time," Mr Willox said.

"All our indications were and continue to be that it was a safe place of work, but what occurred was a terrible tragedy, the details of which we don't know."

On October 4, Dillon died while working in a confined space.

By the time his family were allowed to see him later that day, his body was cold.

"He was all pale. His ears were purple. He went through lots of suffocation," said Xinlei Wu.

"He definitely suffered."

Dillon's mother Guojuan fainted twice in the days following his death. ( ABC News: Jeremy Story Carter )

The Australian Manufacturing Workers' Union, which represents workers at the factory, said Marshall Lethlean made no changes to its safety procedures after the Ai Group audit.

"It's quite disturbing to know that not only the host employer knew about it, but that the direct employer knew about it," said Tony Mavromatis, the Victorian secretary of AMWU.

"We have these rules and regulations for a reason and it's just shameful what has happened here."

WorkSafe Victoria is yet to complete its investigation, so the exact circumstances of his death have not been officially confirmed.

Dillon's co-workers said he was working inside the tank alone, in breach of safety regulations, when he suffocated on argon gas accidentally released from a welding device.

"He's not supposed to be working alone inside the tank like that," Xinlei Wu said.

"He should have someone looking after him all the time."

Dillon Wu's family said they have not been contacted by Ai Group. ( ABC News: Jeremy Story Carter )

Family wants answers, not flowers

Ai Group's August safety audit also raised concerns about a lack of equipment maintenance, unsafe handling of dangerous chemicals, and observed that part of the factory's machinery was not secured to the ground.

It recommended the company carry out a complete overhaul of its safety procedures "in order to meet legislative requirements and reduce the risk of injury to workers".

In spite of the concerns outlined within their own audit, Ai Group's chief executive Innes Willox said the organisation believed Marshall Lethlean was nonetheless a safe workplace to send apprentices.

Innes Willox is the chief executive of Ai Group. ( ABC: Jeremy Story Carter )

"We've had apprentices with Marshall Lethlean now for 17 years," Mr Willox said.

He said Ai Group's training program has a longstanding safety record.

"This is the first death of an apprentice that we've had," he said.

"I'd like to be more expansive but there's an inquiry underway."

Ai Group has not spoken to Dillon's family in the month since his death.

The organisation — whose website reads: "We're here when you need us" — sent flowers through a florist service instead.

"The minimum human morality for the agency is to come over to give us a reasonable explanation," Dillon's father said.

"They should give us an explanation — what's the reason of it?"

Mr Willox said Ai Group had tried to contact the family through Marshall Lethlean.

"That is the way that we were advised to do this," he said.

"We stand ready, our organisation stands ready, to talk with his family at any time."

Ai Group has since contacted the ABC stating its staff had in fact met with members of the Wu family on the day of Dillon's death.

"There was contact on the day of the incident and at the funeral — both highly stressed situations so understandable if they [the family] are unsure about this contact," an Ai Group spokesperson told the ABC in an email.

Dillon Wu's family says he was a fun-loving 20-year-old who was excited about his apprenticeship. ( Supplied )

In a brief statement to the ABC, Marshall Lethlean said Dillon's death on its worksite had left its directors and employees "shocked and deeply saddened".

"There is an ongoing investigation into this matter by WorkSafe Victoria. The company is fully cooperating with this process and will continue to do so," Marshall Lethlean's general manager John Zhang said.

"It is also conducting its own enquiries into the circumstances surrounding the accident as part of its ongoing safety management process. As such, it is not in a position to comment on the causes of the accident at this stage."

Dillon's recent funeral, held in Melbourne's east, was a site of both anger and profound sorrow.

Distraught family and friends believe his death was entirely preventable, and the tragedy has robbed them of a caring, fun-loving young man.



Dillon Wu's close friend Steve Sundaralingam tattooed Dillon's name and birth date on his arm following his death. ( ABC News: Jeremy Story Carter )

Speaking in front of aunts and uncles flown in at the considerable expense of Mr and Ms Wu, Dillon's friend Steve Sundaralingam shared a heartfelt tribute to his close mate.

"I never got the chance to say this bro, but I love you," he said.

Watch the story on the ABC's 7.30 program.