GILLETTE (WNE) — A 31-year-old Gillette man was killed working at a Campbell County coal mine Wednesday.

Jeff A. Wendland and four other workers were adding a section to the boom of a 200-ton crane at Black Thunder mine near Wright. As they were doing so, Wendland was underneath the section when it fell onto the right side of his shoulder and neck area, said Undersheriff Quentin Reynolds.

A mine employee called the Campbell County Sheriff’s Office around noon requesting an ambulance and an air ambulance. Emergency medical services personnel pronounced Wendland dead at the scene, Reynolds said.

The cause of death has been determined as asphyxiation with crushing injuries, said Campbell County Coroner Paul Wallem.

Wendland worked as a millwright at the mine and had been at Black Thunder for 13 years, according to a statement from the mine’s parent company, Arch Natural Resources. He leaves behind a wife and four children.

He was helping to perform a dragline repair when the accident happened, Arch said. The mine is working with federal and state officials to investigate the accident and determine what caused it.

Mining operations were suspended Wednesday but have since resumed.