Three men and five women were in the Ford Explorer. Illinois State Police said all the fatalities were women, and a lack of seat belt use contributed to the fatalities.
"The vehicle rolled over in the ditch, apparently several times. Three of the passengers were ejected," said Illinois State Trooper Brian Windel.
The one-car crash occurred on the westbound lanes of the I-290 at Addison Road, WLS-TV, Chicago, said.
The DuPage County Coroner's Office confirmed there were multiple fatalities, but did not disclose victims' names.
The westbound lanes of the highway were closed after the crash, causing delays for morning commuters, the (Arlington Heights, Ill.) Daily Herald reported.