A one-vehicle rollover on Interstate 57 in Jefferson County Monday afternoon is being blamed on the 56-year-old Missouri driver suffering a medical event while driving.

According to the Illinois State Police, John Garvilla was northbound on I-57 just south of Veterans Drive at Mt. Vernon when around noon Monday he had a medical episode that caused him to lose control of the rental box truck.

The truck drifted off the left shoulder and when Garvilla attempted to bring the truck back onto the roadway while still dealing with the medical issue, he over-corrected and the truck left the right side of the road before it overturned onto its side and came to rest in the right lane and the right shoulder.

All lanes of I-57 were reopened about an hour and 45 minutes later following crash investigation and cleanup.

Garvilla and a 15-year-old male passenger from St. Peters, Missouri both escaped injury.