Worker dies after pipe bursts in Sydney

A plumber has died in hospital after being struck in the head by a burst pressurised water pipe at a central Sydney construction site.

NSW Ambulance said it was called to the iMax theatre worksite at Darling Harbour after 10am on Friday.

The 49-year-old man was treated at the scene for head and facial injuries and was transported to St Vincent's Hospital in a critical condition but subsequently died.

Police are now investigating.

"A crime scene has been established and police are conducting inquiries into the circumstances of the incident," a police spokesperson said in a statement.

SafeWork NSW said its inspectors attended the site as well.

NSW Ambulance Inspector Giles Buchanan told reporters: "The force of the pressure of the water may have caused a loud bang which is why we got some initials reports of an explosion."

Labor called on the NSW government to strengthen draft legislation to make workplaces safer and hold employers to account for any deaths.

Opposition industrial relations spokesman Adam Searle expressed his sympathy for the worker's family and colleagues.

"One workplace death is too many, but this shocking incident is the latest in a spate of workplace deaths that just simply shouldn't be happening. The government has to act," he said in a statement.

Darren Greenfield, the NSW secretary of the Construction, Forestry, Mining and Energy Union, echoed Mr Searle's remarks.

He said the union had previously been alerted to "a range of issues" at the Darling Harbour site.

"It is a disgrace that this keeps happening - how many workers need to die before we have proper industrial manslaughter laws in this country that hold culpable bosses to account?" Mr Greenfield said in a statement, adding developer Grocon had "a shocking track record".

Grocon has been contacted for comment.