IMLAY CITY (WWJ) - A criminal investigation has been launched after an autopsy determined a man who was found dead in a trench collapse in Imlay City did not die from the fall.

Imlay Police say they got a call about a cave-in at a construction site on South Almont, north of Newark, on September 12. When they arrived, officers started digging in the hole and within five minutes found 38-year-old Craig Wagner dead with severe injuries to his head.

Authorities initially thought Wagner died in the trench collapse but now, investigators believe he was buried in the trench after he died.

Dr. Virani of the Oakland County Medical Examiner’s office says Wagner died as a result of contact by the excavating equipment at the scene. He says Wagner's injuries could not have been sustained by the collapse of the site or falling dirt. His examination also revealed that Wagner was dead before he was buried in the hole.

A warrant request has been submitted to the Lapeer County Prosecutor's office to determine proper criminal charges.