Tributes are flowing for the young worker who died when scaffolding collapsed at a construction site in Sydney.
Three days after hosting his 18th birthday party, the family of Sydney apprentice Christopher Cassaniti are planning his funeral.
The formworker was crushed to death on Monday after scaffolding, 15 to 17 metres in height, collapsed on him and a co-worker at a construction site in Macquarie Park.
Prime Minister Scott Morrison on Tuesday morning said the incident was heartbreaking.
"I am just so saddened about the death of young scaffolding apprentice Christopher Cassaniti. To his parents and workmates my heart goes out to you," Mr Morrison tweeted.
Opposition leader Bill Shorten also sent his condolences and described Mr Cassaniti's death as shocking.
"As a father of three, it is incomprehensible what his family must be going through at this time - and I think I speak for everyone when I say they are in our thoughts," Mr Shorten tweeted on Tuesday.
Mr Cassaniti initially couldn't be accessed by paramedics and was pronounced dead at the scene a few hours after the incident.
His colleague, a 39-year-old man, suffered injuries to his lower body and was taken to Royal North Shore Hospital where he remains in a stable condition.
Days before the incident Mr Cassaniti's mother sung the praises of her son, who turned 18 last Wednesday.
"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," she had posted to Facebook.
"To lose their 18-year-old son, new to this industry, early in his working life, and to lose his life doing a job, it's atrocious," CFMEU NSW state secretary Darren Greenfield told Sydney Morning Herald.
Residents took to Facebook to pay their respects to Mr Cassaniti and pass on their condolences to his friends and families.
"You are such a beautiful young man, who like me, was just beginning your life in the world," one Facebook user said.
"I didn't even know this young boy but have been feeling upset all afternoon," said another.
"There are no words... just pure sadness, my heart bleeds with sadness for everyone that is affected by this tragedy," Chris Grech wrote.
Vision that appeared to be filmed shortly after the incident showed tonnes of steel, concrete and meshing strewn over the construction site.
Workers can be seen scurrying to safety as pieces of debris are heard falling to the ground in the vision, obtained by Nine News.
Four Fire and Rescue crews, 10 ambulance crews and two helicopters responded to the scene.
Construction company Ganellen was helping emergency services during the time of the incident.
"This is a tragic incident and our deepest sympathies go to the young man's family, co-workers and friends," a spokesman said in a statement.
"Another injured worker is receiving treatment in hospital and our thoughts and best wishes are with him. All others on site have been safely accounted for."
On Monday evening, friends of the former St Patrick's College student posted tributes in memoriam.
"You were a fantastic bloke and had a heart of gold," Benjamin Betros 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," Bella Mineo said.
A spokesman for construction company Ganellen expressed sympathy to the family, colleagues and friends of the young man.
SafeWork NSW and police are now trying to work out why the scaffolding at the Lachlan's Line apartment complex collapsed.
Construction union CFMEU national secretary Dave Noonan said such an incident shouldn't happen if scaffolding is erected, maintained and loaded property.
"Tragedies like this just shouldn't happen and we can't imagine the grief and sorrow that family are in at the moment," Mr Noonan told Seven's Sunrise on Tuesday.
