An 18-year-old man has died after suffering a "traumatic cardiac arrest" following a workplace incident at a mechanical business in New South Wales.

Emergency services raced to the workshop in Brocklehurst, north of Dubbo, shortly before 1pm on Wednesday after receiving a triple-0 call reporting "an injured man", police said.

The young male apprentice died at the scene.

SafeWork NSW staff have since been out to the business where the teenager died.

"Initial inquiries indicate the worker died when the elevated cab of a truck collapsed," a spokeswoman told news.com.au today.

"Investigations are ongoing."

NSW Ambulance Inspector Adam Parker said the patient "suffered a traumatic cardiac arrest".

"Paramedics performed CPR for more than 20 minutes," he said.

"Despite the best efforts of paramedics and his workmates, the young man tragically died."

Insp Parker said staff arrived on scene within minutes of the 12.40pm phone call.

He said it was the type of job that proves difficult for the families of patients and for paramedics.

"(A) NSW Ambulance Chaplain arrived on scene to provide emotional support for the family who attended the worksite," he said.

He urged workers to ensure the safety of themselves and those around them while on a site.

A NSW Police spokeswoman said a report will be prepared for the information of the coroner.