GLEN CARBON — Authorities are continuing to investigate the cause of a deadly crash Wednesday morning in which a semi-trailer veered of eastbound Interstate 270 veered off the roadway and struck a tree, killing the driver.

Madison County Coroner Stephen Nonn has identified the victim as 47-year-old Brian E. Westerfield, of Freeburg.

According to multiple witnesses, Freeburg abruptly veered off the roadway to the left, crossing the center median into the eastbound lanes of Interstate 270. The truck continued traveling Southwest off the roadway, striking a tree head on, causing the semi to burst into flames.

An autopsy was conducted Thursday, however a precise cause of death is not being prescribed pending completion of carbon monoxide studies.

Evidence of coronary artery disease was found, however it has not been determined that heart disease caused or contributed to the crash.

Additionally, routine toxicology testing for the presence of alcohol and drugs will be performed at a later time.

Funeral arrangements are under the direction of Renner Funeral Home of Belleville.