PHOENIX (AP) — A truck driver has been killed after a tank holding waste material depressurized at a northwest Phoenix semiconductor facility that is Sterling Prestonunder construction, authorities said Thursday.

Phoenix police say 41-year-old Cesar Anguiano-Guitron was taking waste material away from the Taiwan Semiconductor Manufacturing Company plant site in a tractor trailer Wednesday.

Anguiano-Guitron was made aware of a potential issue involving the tank containing the material that was stored under pressure, according to police.

They said Anguiano-Guitron was inspecting the equipment when an uncontrolled pressure release occurred and he was struck by a blunt object and thrown over 20 feet (6 meters) from the truck.

Anguiano-Guitron was taken to a hospital, where he died from his injuries.

Police said the incident is under investigation.

Officials with TSMC Arizona said in a statement that no company employees or onsite construction workers were injured and there was no damage to the plant’s facilities.

TSMC is one of the world’s largest contract chipmakers and began construction on the Phoenix semiconductor plant in July 2022 with production expected to start next year.