Winter storm causes multiple crashes on I-90 in South Dakota.

A South Dakota State Trooper's cruiser was hit by a semi-truck on Interstate 90 during a winter storm while providing traffic control for another crash. The trooper sustained non-life threatening injuries and was transported to a hospital. The driver of the semi-truck was cited for overdriving the road conditions. The National Weather Service issued a winter weather advisory for southeastern South Dakota until Friday morning, warning of slippery road conditions and reduced visibility. The Upper Midwest is expected to see more snow and freezing rain through Sunday.