In this photo provided by KCCI-TV, emergency personnel tend to vehicles on Interstate 35 in Ames, Iowa, after dozens of vehicles collided on the snow-covered freeway Monday, Feb. 5, 2018, forcing the closure of the southbound lanes. Pic/AP/PTI

A winter storm plowing through the U.S. Midwest caused several deaths in Iowa and Missouri from car crashes as the weather snarled highways and cancelled hundreds of flights at Chicago's busy airport, according to authorities and local media. In Iowa, six people died on Monday in crashes throughout the state, including one that left the I-35 highway jammed near Ames, the Des Moines Register reported.