This is the harrowing moment tradesmen frantically tried to save two colleagues trapped under a mountain of collapsed scaffolding at a construction site.
Piercing screams echoed around the site in north-west Sydney as tradesmen in hard hats and high-vis jackets rushed to free the men.
New footage of the frenzied scene shows men forming a human chain to remove the rubble as fast as possible.
Frantic workers desperately tried to free their colleagues for 20 minutes until the wailing stopped and they were ordered to move away.
Harrowing: This is the harrowing moment tradesmen frantically tried to save two of their friends trapped under a mountain of collapsed scaffolding at a construction site
Frantic: Workers desperately tried to free their colleagues for 20 minutes until the wailing stopped and they were ordered to move away
Tragic: Christopher Cassaniti, 18, died in the collapse at Macquarie Park, north-west Sydney on Monday. He is pictured on holiday in Hawaii
Happy family: Christopher Cassaniti (centre) celebrated his milestone birthday with proud parents Patrizia and Rob
Patrizia Cassaniti (pictured with her husband at the scene) runs a coffee and food truck near the construction site where her son Christopher was killed
On his birthday, Mr Cassanti's mother paid a moving tribute (picutred) to her son. She wrote on Facebook: 'Today, 18 years ago, was one of the most terrifying moments of my life that was then fulfilled with much relief, joy and happiness'
'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,' worker Albert Muscat told 9News.
Christopher Cassaniti, 18, died in the collapse at Macquarie Park on Monday after he fell from an eight-storey building and became trapped under twisted steel and concrete.
His 39-year-old colleague was pulled from the debris and raced to hospital in critical condition.
Devastated friends and family paid tribute to Mr Cassaniti on Monday night.
The young man recently started his first ever job at the site and was pictured in videos celebrating his 18th birthday with workmates on March 27.
On his birthday, Mr Cassanti's mother posted a moving message on Facebook about her son.
She wrote: 'Today, 18 years ago, was one of the most terrifying moments of my life that was then fulfilled with much relief, joy and happiness.
'Christopher Cassaniti was born 2.7kg and 47cm and my tiniest baby has now grown to be the tallest of the whole family in both sides. He is compassionate and shy yet strong and forever helpful.
'We wish you all the best that the world can dish out and May God be forever in your heart and Bless you with much Joy, Happiness and most importantly health.
'I love you. Happy 18th Birthday Christopher, always Mum, Dad (Rob Cassaniti) and Brothers Adriano Cassaniti and Michael Cassaniti.'
Christopher Cassaniti (pictured) celebrated his 18th birthday with workmates last Wednesday five days before his life was tragically cut short at the construction site he was working at
Heartbroken friends have paid tribute to Christopher Cassanti (pictured with his mum)
Another man, 39, rushed to hospital in a critical condition (pictured) after a scaffolding collapse at a Sydney construction site
Shattered workers comfort each other at the Macquarie Park apartment block on Monday afternoon
One worker wipes away tears while another receives a comforting hand from his colleague
Construction Forestry Mining and Energy Union (CFMEU) state secretary Darren Greenfield told reporters on Monday the boy's parents were shattered.
'As you'd expect, they're devastated to lose their 18-year-old son.'
'He's new to this industry, early in his working life. To lose his life doing a job is atrocious.'
Tributes poured in for Mr Cassaniti, whose mother runs a mobile coffee van near the construction site.
'You were such a ball of energy and so hard working, you will be sorely missed by all your family and friends. Nothing more could I have asked for in a little brother,' his older brother Adriano posted on Facebook on Monday.
His mother also paid tribute to her 'compassionate and shy, yet strong and forever helpful' son when he turned 18 just days earlier.
'We wish you all the best that the world can dish out and May God be forever in your heart and bless you with much joy, happiness and most importantly health,' Mrs Cassaniti posted.
Benjamin Betros added: 'You will be dearly missed by all mate. You were a fantastic bloke and had a heart of gold.'
Christopher's devastated parents Rob and Patrizia Cassaniti at the tragic scene on Monday
Christopher Cassanti (pictured celebrating his 18th birthday with workmates last Wednesday) has been remembered as a friend who saw the best in everyone
'Today I am crying because I have lost a person who occupied a very special place in my heart,' Mr Cassaniti's kindergarten friend Bella Mineo posted on Facebook.
'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. Those special memories of you will always bring a smile to my face. It hurts me that someone so precious had to pass.'
Family friend Damion King, 16, told reporters he last saw Mr
