MILACA, Minn. (WCCO) — A worker was killed in an industrial accident in Milaca, Minn. Thursday morning.

According to the Mille Lacs County Sheriff’s Office, 41-year-old Scott Armstrong of Long Prairie, Minn. was killed while working on a large gravel conveyor belt.

Authorities said Armstrong, who was working at a gravel pit operated by Knife River Construction Company, was struck in the head by a large wheel.

He was pronounced dead, and a medical examiner will determine the exact cause of death.

The sheriff’s office said the incident remains under investigation.