Major Crash investigators are probing two deadly incidents in WA’s Pilbara region.

The first occurred on Thursday, when a Toyota HiLux ute and a road train collided on the Great Northern Highway, about 80km northwest of Newman, just after 4.30pm.

The Toyota driver, a 30-year-old man, suffered critical injuries and died at the scene.

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The 48-year-old truck driver was not injured in the crash, which closed a long stretch of the remote highway for several hours.

At around 12.20am on Friday, a pedestrian was struck by a car on Throssell Road in South Hedland, in northwestern WA.

The 45-year-old man was rushed to hospital with critical injuries, where he later died.

Major Crash investigators have appealed for information regarding both fatal incidents.

Anyone with details or video footage is urged to contact Crime Stoppers.