The Coast Guard closed a stretch of the swollen Mississippi to barge traffic today in a move that could cause a backup along the mighty river, while authorities farther south in Memphis went door to door, warning about a 1,000 households to leave before they get swamped. Emergency workers handed out bright yellow fliers in English and Spanish that read, "Evacuate!!! Your property is in danger right now."
Because of levees and other flood defenses built over the years, engineers said it is unlikely any major metropolitan areas will be inundated as the water pushes downstream over the next week or two, but farms, small towns and even some urban areas could see extensive flooding. "It's going to be nasty," said Bob Bea, a civil engineer at the University of California-Berkeley who investigated levee failures in New Orleans after Hurricane Katrina in 2005. (Read more Coast Guard stories.)