Multiple people have been injured after a building collapsed in an inner-Sydney suburb and sparked a major emergency response. 

Part of a concrete retaining wall collapsed near a Shell service station on Wattle Street, at Ultimo, shortly before 11am on Monday.

Several workers were trapped beneath the rubble while debris crashed onto vehicles, including a Modus Projects ute, parked near the service station. 

A Modus Projects spokesman told Daily Mail the building was next to a site where they were undertaking works.

‘No Modus employees or contractors were injured as a result of the collapse,’ he said. 

One hatchback was also completely squashed while several workers’ cars parked just metres away escaped damage.

NSW Ambulance told Daily Mail a man in his 60s was rushed to Royal Prince Alfred Hospital and a man in his 30s was transported to St Vincent’s Hospital, both in a serious condition, while five others were assessed at the scene.

The collapse is being treated as a possible workplace incident. 

Footage showed two paramedics talking to a man, who appeared to be a tradie, as he sat on a kerb with a towel around his neck.

He was then led into an ambulance.

Uber delivery driver Mahrouk Abdou said he had been parked beneath the wall just minutes before it collapsed. 

‘I heard a lot of not normal noise, so I moved my scooter and two minutes later, the wall fell,’ he said. 

‘I was shocked and surprised.  

‘I feel lucky, but I hope the people who are injured will be safe.’ 

A NSW Fire and Rescue spokesman said the service station was shut down and ‘the buildings around have been evacuated’, with more than 35 people ordered to leave. 

Emergency crews are monitoring the area for potential electrical and gas risks, while firefighters, urban search and rescue specialists and drone operators remain at the site. 

The warehouse was previously used as a rehearsal studio and had been approved for demolition to make way for a multi-storey mixed-use development. 

Daily Mail has contacted SafeWork NSW for comment.