A truck driver who was pulled over by police on a road in Sydney's west got out of his rig only to be hit by a semi-trailer and killed, police say.
Police have launched a critical incident investigation into the man's death on Vardys Road in Kings Park about 10.20am on Thursday.
A NSW Police spokeswoman said officers from the Traffic and Highway Patrol had stopped the truck on Vardys Road, near the intersection with Turbo Road. The driver, who was believed to be aged in his 40s, got out of his vehicle in an attempt to secure his load when he was struck by the semi-trailer, police said.
A witness said the man was run over by the semi-trailer, and was lying unconscious on the road.
Paramedics attempted to revive the critically injured man, but he died at the scene.
Police closed off Vardys Road and the CareFlight helicopter landed on the road, but soon after returned to base.
The driver of the second truck was taken to hospital for mandatory blood and urine testing.
A critical incident team from North West Metropolitan Region is investigating the circumstances surrounding the incident.
That investigation will be subject to independent review and a brief will be prepared for the information of the Coroner.
Police have urged witnesses to contact Crime Stoppers on 1800 333 000.