Authorities managing dams in Tennessee and Mississippi must make difficult decisions as floodwaters swell along the states’ rivers; the surging water pressing against the dams has to be released at some point, and when it does, it often spells disaster for individuals living downstream from the dams.Case in point: two large homes slid into the flood-swelled waters of the Tennessee River over the weekend.

Source: Tennessee flooding: 'Unprecedented' floods make homes slide into river