The Iowa River overflowed its banks about three months after the murders. Most locals sensed the threat of rising water. In Iowa City, a vibrant college town in the southeastern corner of the state, fog usually doesn’t come until spring, but that winter, Iowans awoke to barren crop fields and highways draped in thick clouds—a result of warm, wet air carried north from the Gulf of Mexico.
Here, like much of the Midwest, there is little protection from the weather. Smooth limestone bluffs border eastern Iowa’s waterways, but once you enter the populous river valley, paper-flat farmland—tiled and stripped of its natural, complex prairie root system—stretches on for miles. By June 2008, unrelenting rain turned the rich soil into mud pastures.
The river widened until it was nearly level with the University of Iowa’s grassy grounds while, two miles away, the Coralville reservoir swirled at the concrete edges of the spillway. Then it came…