The heartbroken family of an 18-year-old apprentice killed at a construction worksite share their anger at his death.

In an interview with 60 Minutes reporter Tara Brown, Patrizia and Rob Cassaniti reveal their anguish at the devastating loss of their son, Christopher, and their determination that his death will not in be vain.

“It shouldn’t have happened,” the emotional father says.

Patrizia and Rob Cassaniti said their son's death should never have happened. (60 Minutes)

“It was such a big building construction corporation. How does this happen?”

Christopher Cassaniti, who had just celebrated his 18th birthday, was killed when a 17-metre high scaffolding tower collapsed at his worksite in Macquarie Park in Sydney, trapping him beneath a massive pile of steel.

The grieving mother is determined that her son's death will not bee in vain. (60 Minutes)

“I think it’s one of the worst things that can happen in life is to lose a child,” Mrs Cassiniti says.

“They always say that, and it’s true.”

Mrs Cassiniti operated a coffee cart just metres from Christopher’s worksite, which serviced the construction workers at Macquarie Park.

The teenager was trapped beneath a massive pile of steel. (60 Minutes)

On hearing of the incident, she rushed to the construction site. She describes the panic, despair and disbelief she felt on discovering her young son was trapped beneath the rubble.

“I was in total denial. I just screamed and I said, ‘No. It's not possible, he’s too young.’”

“I said, ‘He's 18. He's got a strong heart. Go back out there and do whatever you can.’”

Tragically, Christopher could not be saved.

The proud parents are devastated by the loss of their son. (60 Minutes)

While it could take years for the investigation to determine the exact cause of his shocking death, it has led to renewed calls for industrial manslaughter charges to be brought against operators of any worksite where gross negligence results in death.

The laws, if implemented, could see negligent bosses go to jail.

The Cassaniti family tell 60 Minutes they’ are determined to fight for those responsible for their son’s death to be held accountable.

Patrizia Cassaniti said her son's death was one of the worst things that can happen to a mother. (60 Minutes)

“They should feel the same pain we’re feeling,” Mr Cassiniti says.

“Make them understand that their decision cost someone’s life - our boy’s life.”

The construction site at Macquarie park in Sydney where Christopher died. (60 Minutes)