ST. CLAIR COUNTY. — The death early this morning of a woman struck by two semi trucks on Interstate 64 is under investigation, with authorities saying it appears she jumped from an overpass.

According to Illinois State Police, the woman’s death appears to be a suicide.

They say they responded around 2:30 a.m. and found a vehicle running on the North Main Street overpass with a suicide note inside the vehicle.

There was a step-stool next to the railing, indicating the woman may have jumped, according to authorities.

ISP says the driver of the first semi that hit the woman told authorities she “was lying flat on the roadway” at mile marker 18 on the interstate, near O’Fallon.

The crash caused heavy traffic delays early Friday morning around 6 a.m. By 8 a.m., all westbound lanes were cleared.

No other injuries were reported.