hitting the northern tier:

(Reuters) - A fast-moving storm system that produced at least one tornado in Illinois threatened some 53 million people across 10 Midwestern states on Sunday, U.S. weather officials said.

"A confirmed large and extremely dangerous tornado" was spotted near Washington, Illinois, located about 145 miles southwest of Chicago, the National Weather Service said.

Images on television showed extensive damage in Washington, Illinois, with structures reduced to rubble and cars turned upside-down.

It came out of a fast-moving storm system that was headed toward Chicago and threatened a large swath of the Midwest with dangerous winds, thunderstorms and hail, U.S. weather officials said.

At Chicago's Soldier Field, where the NFL's Bears were playing the Baltimore Ravens, officials told fans to seek shelter due to hazardous weather conditions.

"We obviously have a very dangerous situation on our hands and it's just getting started," Laura Furgione, deputy director of the National Weather Service, told reporters in a conference call.

The weather service advised that the tornado outside Peoria, Illinois, would affect mainly rural areas, with mobile homes likely to be destroyed and trees likely to be uprooted or snapped.