A man has died from "crush injuries" in an industrial accident in western Sydney this morning.

Emergency services were called to a timber pallet factory in St Marys at 5.40am and found a 30-year-old man suffering serious injuries to his head.

"He was stuck in a piece of machinery," a NSW Ambulance spokeswoman told news.com.au.

A NSW Police spokesman said: "Inquiries revealed a 30-year-old man suffered serious injuries on site and died at the scene."

Officers are on the scene at Enviro Pallets on Forrester Rd.

SafeWork NSW is investigating.

"Safework is attending a worksite at St Marys today after a worker became trapped in a machine," a spokeswoman for the workplace authority said.

"The worker sustained crush injuries."

There has been a spate of workplace deaths in Sydney over the past few weeks.

A 40-year-old man was killed on Saturday morning when he was sucked into a woodchipper in Lindfield on the city's north shore.

News.com.au understands two men had left their colleague working by the chipper.

When they returned, the man - named in media reports as Fijian national Samuela Cirivakayawa - had vanished but a pool of blood was visible.

In late August, 38-year-old Mohamad Riche fell to his death at a building site near Penrith.

He had been working on the roof of the Geneva Jordan Springs development on Jubilee Drive when he fell approximately seven floors down a lift shaft onto the concrete below.

Specialist paramedics abseiled down but confirmed to his colleagues he had died.

More to come.