A tradesman has recalled horrific details of how a co-worker was crushed to death by a concrete pump at a construction site.

Paulo Mau’u, 40, and Aymen Elahmad , 30, were critically injured at the Meriton construction site at Carlingford, in Sydney’s north-west, on Tuesday.

It’s understood a concrete pump fell onto the the pair. 

Mr Mau’u later died, while father-of-three Mr Elahmad continues to fight for life in Royal North Shore Hospital with severe injuries, including paralysis and punctured lungs.

Friends revealed on Wednesday that he will undergo ‘delicate’ spinal surgery.

Meriton boss Harry Triguboff paid a visit to the worksite afterwards to speak with shocked workers.

‘I heard a big bang, turned around and saw two guys under it. One’s legs were all bent,’ a worker told Seven News.

‘One was knocked out unconscious.

‘I was in shock. I didn’t know what to do.’ 

Sydney tradie Paulo Mau’u has been remembered as a dedicated family man

Two tradies were crushed by a concrete pump at a construction site in Carlingford on Tuesday (scene pictured).  Mr Mau’u was killed while the other is fighting for life

Footage emerged online on Wednesday of a crane in operation at another Meriton construction site in honour of Mr Mau’u, as a group of tradies watched on.

‘This is for you, my uso (brother),’ the tradie captioned the footage.

The tragedy has sparked an outpouring of tributes for Mr Mau’u, who has been remembered as a dedicated family man who put others first.

He described himself on social media as a ‘proud Samoan’ who migrated to Australia from New Zealand.

‘He was a hardworking father who left for work like any other day, not knowing it would be his last,’ one friend wrote.

‘Dedicated to providing for his family, he never complained and always put others before himself.’

‘His sudden passing is a painful reminder of how precious and fragile life is. 

‘He will be remembered not just for his hard work, but for the love and strength he gave his family every single day.’

Others saw the tragedy as a reminder to never take life for granted. 

Father-of-three Aymen Elahmad (pictured) continues to fight for life in hospital

Mr Mau’u (pictured) was a ‘proud Samoan’ who migrated to Australia from New Zealand

‘We never really know when the last time you see someone is the “last time”, a mate wrote.

‘Couldn’t believe the news. Will forever miss your good vibes & energy. Love ya, uso. You truly will be missed.’

Friends gave an update on Mr Elahmad’s condition on Wednesday as he prepared to undergo a ‘critical’ operation on his spine

As he was the sole breadwinner for his young family, a fundraiser has been set up to assist with medical costs and living expenses.

‘He’s always been the one to provide for his family, working hard in the field, and now it’s our turn to come together to support him and his loved ones,’  the fundraiser states.

‘The road to recovery will be long, and Aymen’s family will need all the help they can get.

‘Aymen is the kind of person who would do anything to help others, and now we want to show him the same kindness and generosity he’s always shown. 

‘Our goal is to provide as much support as possible to help Aymen focus on his recovery and his family focus on healing.’

The fundraiser had raised almost $4000 within hours. 

An investigation into the workplace tragedy at Carlingford is now underway

Australia’s biggest unit developer is ‘fully cooperating’ with SafeWork NSW, which has launched an investigation into how the tragedy unfolded. 

‘Our hearts go out to their families, friends, and colleagues during this incredibly difficult time,’ a Meriton statement read.

‘We extend our deepest condolences and stand with them in their grief and pain.’

The tragedy unfolded at the construction site of The Carling – a master-planned community which will consist of 629 units across seven high-rise towers.

It’s the same Meriton worksite where an unstable crane almost toppled in June due to powerful winds.

The incidents shut down Pennant Hills Road – one of Sydney’s busiest roads – and forced the evacuation of hundreds of residents from nearby unit complexes.