A head-on collision on a Chicago-area tollway claimed the lives of a 24-year-old Wisconsin woman and her toddler son, authorities say.

Illinois State Police say Nicole Polk, of Algoma, Wis., and her 16-month-old son, Tevin Temple, were declared dead on the Tri-State Tollway in Lake County, Ill., in what may be an alcohol-related crash, the Chicago Tribune reported.

Also critically injured in the crash was Polk's 2 1/2-year-old son, whom police said. State Police Master Sgt. Susan Ewald told the Tribune Polk was not wearing her seatbelt and open alcohol was found in her car after the crash.

Police said Polk's car crossed a grassy median between the northbound and southbound lanes of the tollway, which also is Interstate 94, and crashed head-on with an oncoming vehicle whose driver and three passengers sustained only minor injuries, the newspaper said.