 Heavy rains from thunderstorms, strong winds, and plenty of tornado warnings were all part of what the National Weather Service called a complex of destructive storms that moved from eastern Iowa into Illinois and Indiana. In the Chicago region, sirens noting the bad weather sounded on cell phones and televisions in late evening as officials warned numerous tornadoes were in the region. A ground stop was issued for O'Hare Airport. A tornado warning was even issued for Chicago's downtown.