"It looks like a bomb just went off," Beenders wrote on Twitter before posting a picture of the storm damage.
In Chicago, residents were warned to stay off the streets as the strongest winds, approaching 60 miles per hours, swept through the area.
By mid-afternoon at least 230 flights had been cancelled from Chicago's O'Hare airport.
The Illinois Emergency Management Agency said they were responding to at least 11 counties that have reported tornado touchdowns.
The Ameren company, which provides electricity throughout Illinois, told ABC News radio that 144,500 people were without power throughout Illinois.
The ComEd electric company, which serves the Chicago area, told WLS-TV that there had been 79,000 outages.
The Associated Press contributed to this report.