At least three vehicles westbound on I-80 in Grundy County, including semis, are involved.
Two people are confirmed dead, according to ISP.
A preliminary investigation indicated that five vehicles were involved, including three traveling westbound and when two others traveling eastbound near milepost 109, ISP said.
One vehicle in the westbound lanes crashed into the rear-end of another vehicle also in the westbound lanes, causing it to travel through the center median and into the eastbound lanes, police said. The car that had been struck then hit another vehicle, which rolled over across the center median into the westbound lanes and struck a fourth vehicle. A fifth vehicle was hit by debris from the crash.
The car that had initially been rear-ended carried a driver and a passenger, who were pronounced dead, police said.
No other injuries were reported.
State police were diverting traffic off the interstate in the area because. It was closed for an extended period of time while officials investigated, but reopened around 5:00 a.m. Saturday.