Christopher Cassaniti, 18, was killed when a nine-storey scaffolding tower collapsed on top of him and a workmate at a building site in Macquarie Park in April.

He was trapped under the heavy rubble with his mate, fellow tradie, Khaled Wehbe, and the two held hands for twenty minutes while Christopher screamed for help.

“(He was) asking for help,” said Darren Greenfield, the NSW state secretary of the Construction, Forestry, Maritime, Mining and Energy Union (CFMEU).

“Asking for help, asking for his mum. It’s very hard. Very hard. An 18-year-old-boy.

“I mean you see grown men crying, and you just think ‘not again, not another one, not another person not going home tonight’,” Mr Greenfield said.

Khaled and Christopher lay under the wreckage, yelling for help, and holding hands. While Khaled was terribly injured in the accident, he survived. Christopher was suffocated by the weight of the scaffolding, and he died from asphyxiation.

Six weeks after his death, his parents, Patrizia and Rob, telling 60 Minutes losing their “shy boy” from their tight knit family has left emptiness in their lives.

As more details emerge about warnings sent to the construction company about safety concerns, his grieving parents are stunned and furious, and say they’re determined to fight for justice for their son.

“They should feel the same pain we’re feeling,” Patrizia told 60 Minutes. “Make them understand that their decision cost someone’s life — our boy’s life.”

Patrizia and Christopher were close, and worked together at the Macquarie Park site, where she operated a coffee van.

On the day of the accident, however, she’d decided to take a day off.

She heard news of an accident, and panicked. As she rushed to the worksite, her panic intensified. She said she “couldn’t breathe” as she arrived, and people began to tell her Christopher was trapped in the rubble.

A policeman then approached her, saying the words no parent could bear to hear.

“‘Mrs Cassaniti, unfortunately we couldn’t do anything for your son. And he has passed away,’” she told 60 Minutes.

“And those words just keep ringing in my head constantly,” Patrizia said. “And I was in total denial. I just screamed.”

“Because I thought it’s not possible. You know? It’s not possible that he has died. So when Rob walked through the door, he saw my face and he says, ‘What’s wrong?’ And I just said, ‘He didn’t make it’.”

The coroner told Rob and Patrizia their son Christopher died after of asphyxiation after his lungs were crushed by the force of the collapsed scaffolding on top of him.

When they asked if their son had been in pain, they were told that yes, he would have experienced some pain, but it’s possible that the adrenaline in his system would have lessened his suffering, and because he was suffocating, it’s likely he would have been going in and out of consciousness.

His parents then described having to identify Christopher on the day of the accident.

“I’m just looking at him and thinking it can’t be,” she told 60 Minutes. “You’re looking for signs of life and you can’t, and that’s hard. That’s really hard. It’s hard.

“He still looked beautiful, even like that.”

“He still looked the same,” Rob agreed. “He still looked beautiful. He was content. Like he even had a little smile on his face, but you know, as a parent you don’t want that.”

“You don’t want to see that, but unfortunately we had to. It was the toughest thing I’ve ever done.”

It has now been revealed that the construction company, Ganellen, had been warned about its scaffolding being unsafe in emails and complaints.

The cause of the collapse is now under investigation.

Mr Greenfield said accidents like the one that killed Christopher most often happen because of corners being cut to save time and money.

Patrizia and Rob have sworn to continue their battle to see justice through, even if it takes years.

“I promise you to continue until it’s done, because Christopher and all others that have died on the job site will not have died in vain,” Patrizia said.

“It’s just got to be a law. I want to call it Christopher’s Law,” she told 60 Minutes, suggesting a jail term for those responsible for workplace deaths that occur through negligence.

“I’ve got a life sentence,” she said.

“They should feel the same pain we’re feeling. Make them hurt.”