One trailer of the semi went over the embankment near the 23-mile marker and into the creek next to the road.
According to Clay County Search and Rescue official Brandon Sciotto, the unidentified driver of the semi apparently fell asleep behind the wheel. The driver sustained minor injuries and was taken to St. Vincent Clay Hospital.
Boxes believed to be containing organic peroxide, a material that has highly flammable and volatile qualities, were found in the water, leading to the calling of a Vigo County Hazmat Unit.
Authorities began monitoring traffic around 7:45 p.m. near the eastbound on- and off-ramps. All westbound lanes and ramps remained open.
Close to 8 p.m., all eastbound traffic lanes and the ramps on I-70 were closed because leakage of diesel fuel, along with rainfall, were creating slippery road conditions.
The eastbound on-ramp at State Road 59 and I-70 was closed.
Traffic was backed up past Billville Road extending into Brazil. Officials with the Brazil City Police Department said they would dispatch officers to help with traffic control.