The family who lost their teenage apprentice son in a horrific workplace accident say they are in horrendous pain and hope lessons will be learned from the tragedy.

Christopher Cassaniti, 18, died when a massive pile of scaffolding and building materials fell on him and another worker, 39, at a construction site at Sydney’s Macquarie Park on Monday.

More than a dozen emergency crews rushed to the site — a mixed-use residential and commercial development project — and managed to free the older man after an hour. He remains in a stable condition in Sydney’s Royal North Shore Hospital.

Christopher had turned 18 just days ago and was an apprentice form worker.

His father said in a statement they were left devastated and empty by the loss of their son.

In a tragic twist, his mother had been visiting the delivering coffee. Both parents were at the scene yesterday afternoon.

“Christopher was a gentle, kind and hardworking young man full of life and love for his family,” the statement read.

“He was adored by everyone who was lucky enough to meet him.

“While nothing can bring our son back, we don’t want his death to be just another statistic.

“No other family should have to go through this horrendous pain. We ask that the government step in and take immediate action and implement stringent measures regarding safety on construction sites.

“Crucial safety checks and procedures need to be at the front and centre of every construction site. We await the outcome of the investigation as to what went wrong.

“We will miss him dearly. One death is too many.”

Christopher and the other worker became trapped beneath a mountain of twisted steel and cement bricks that fell from 17m up in Epping Road just after 12.20pm yesterday.

TRADIES PLEAD WITH COPS

Footage from the scene shows the tense stand-off between police and tradies, with one worker heard screaming “my brother is down there”.

The Facebook footage shows police officers trying to calm workers down and yelling into a megaphone to maintain order after frantic tradesmen argued with cops, saying: “You’re wasting time. We need access”.

“Everybody, we need you guys to help us,” one officer can be heard saying in response.

However, one tradesman hit out saying: “We are helping. You’ve got a whole army here - we’re ready”.

Another police officer responds: “If we move the wrong piece more will collapse. It’s like a jigsaw puzzle”.

“Give us instructions then, let’s do something,” a worker replied. “Come on let’s start.”

A police officer responds, warning: “If you move anything, boom, collapse...”

It’s then that a harrowing scream of “my brother is down there” can be heard from an unknown tradesman.

A police officer can then be heard saying: “Listen, listen. Let the ambos stabilise it and as soon as they say ready we’ll get it.”

According to The Daily Telegraph, one officer pulled capsicum spray from their holster and held it “at the ready” while another officer pulled out a baton before senior officers calmed the situation.

Further footage shows the moment construction workers frantically searched for their colleague buried under the collapsed scaffolding.

A cacophony of anguished yells can be heard in the clip that shows dozens of tradies watching on in shock next to the massive pile of collapsed metal.

Rescue workers continued a “delicate” operation to free Christopher but struggled to reach him due to the sheer amount of debris. He was pronounced dead at the scene.

This morning, CFMEU construction and general national secretary Dave Noonan said the death was caused by a “catastrophic failure of a scaffolding”.

“Scaffolds are working platforms for workers to work safely off,” he told the Today show this morning.

“If they are erected safely, maintained properly and loaded properly and within their capacity then they do not collapse.”

The teen has been remembered by friends as an “angel” who always looked after everyone.

Family friend Damion King, 16, said they had only just been celebrating his 18th birthday on the weekend.

“My dad called my sister first and she called my mum and she just started crying,” Mr King told news.com.au.

“That’s when I found out and 30 minutes later his brother posted RIP Chris. It’s really sad.

“We used to go on holidays together. He always looked after everyone, he was very kind.

“He just bought a car and was just starting his life. It’s so sad to see him lose everything.”

On Facebook, family friend Bella Mineo said she would “always love” her friend Christopher.

“Today I am crying because I have lost a person who occupied a very special place in my heart,” she said.

“You have been my friend since the first day of kindergarten. Words can’t express how much this hurts. You were full of positivity, always smiling, always seeing the best in everyone. You are an angel. It hurts me that someone so precious had to pass. Forever in my heart.”

Darren Greenfield, state secretary of the construction industry union CFMEU, said Christopher’s distraught parents arrived just before police confirmed the tragic news.

“As you’d expect, they’re devastated to lose their 18-year-old son,” Mr Greenfield told news.com.au.

“He’s new to this industry, early in his working life. To lose his life doing a job is atrocious.”

Mr Greenfield said he understood the men were on the ground when the structure collapsed on top of them.

“The scaffold has come down from about 15 (to) 17 metres,” he said.

“Some bricklayers working up there, they jumped back onto the balcony otherwise they wouldn’t be here now.

“Unfortunately these workers were working on the ground, as far as I’m aware, and it’s come down on top of them. You can imagine, 17 metres high, four layers of scaffolding, that’s a lot of steel coming down.”

A worker who rushed to help the men after the collapse told news.com.au that he was “shattered and heartbroken”.

“We got to them and nearly had them but we all got rushed, told to jump off,” the man said.

“There was nothing else we could do. We could hear them calling for help. We tried our hardest to get the scaffolding and bricks off them and we managed to reach them but were told to back off once the fireys and stuff came.

“He was a good young man. Just eager to do his work. He always had a smile on his face, just a bright young man. I’m speechless.”

Mr Greenfield said the workers, many of whom remained gathered at the site well into the afternoon, were in a state of shock.

“I’ve seen probably 14, 15 deaths in the construction industry so I know what they’ve seen and I know by the looks on their faces and what they’re saying …”

Worker Albert Muscat told Channel 9 he could hear the men screaming for help after the collapse.

“We started cutting with the grinders and hammers until about 20 minutes later we couldn’t hear screaming anymore, that’s when the supervisors told us to move out,” he said.

It’s believed the scaffolding was in the process of being removed as the project nears its completion.

Steve Vaughan, acting superintendent of NSW Ambulance, said it was an “absolutely chaotic and emotionally charged scene” when paramedics arrived.

“It took some time to ascertain what had happened,” Mr Vaughan said.

“They were able to treat and stabilise one of those patients who has since been transported to (hospital) in a critical condition.”

A witness who was eating lunch next to the site when the collapse occurred told 10 News it was a “scene of panic”.

In a statement, construction company Ganellen said it had promptly worked to assist emergency workers at the site of the $220 million development.

“Our immediate concern and focus is on the safety of our people and according for those who were in the vicinity of the accident, and ensuring the site is safely secured,” the builder said in a statement.

Police have established a crime scene. SafeWork New South Wales has also sent investigators to the site.

“While the cause of the collapse is unknown at this stage, SafeWork is employing significant resources to fully understand how this tragic incident occurred,” it said in a statement.

The development project was sold by Landcom to Greenland in 2017.