text:  With some major rivers still rising amid heavy rain, parts of the Midwest remain under the threat of severe flooding. CBS's Tom Hanson is in Minnesota, where water crashing into and around a dam has swept away most of a nearby home. The Midwest is experiencing more days of extreme rainfall, events expected to be wetter and more intense due to climate change. Just as sobering, only 4% of U.S. homeowners currently have flood insurance. In the Midwest, it's less than 2%.