Storms barreling across the heart of the United States continue to threaten rain and pose flooding risks after causing at least one death when a man apparently was struck by lightning in Wisconsin.

At least 32 people have been killed in a monster storm sweeping across much of the U.S. Kansas authorities said eight people died in a highway pileup caused by a dust storm Friday.

A line of severe thunderstorms and tornadoes that swept across the north-central U.S. last week has been classified by the National Weather Service as a serial derecho — the first on record December.