SPRINGFIELD, Ill. (WCIA) — A 56-year-old man was found dead over the weekend in a semi-truck, the Sangamon County Coroner announced on Monday.

Coroner Jim Allmon said the man was pronounced dead after he was found on Saturday in a parking lot near Dirksen Parkway and Stanford Avenue. An autopsy performed on Monday found no signs of injury or trauma.

The man’s identity is being withheld until his family is notified.

Allmon said the cause of death is still unknown as toxicology testing is pending. The death remains under investigation by Allmon and the Springfield Police Department.