McEWEN, Tenn.—Catastrophic flooding in Middle Tennessee left at least ten people dead and dozens missing Saturday as record-shattering rainfall washed away homes and rural roads, authorities said. Business owner Kansas Klein watched in horror from a bridge Saturday morning as cars and entire houses were swept down a road in Waverly, a town of about 4,500 people that Klein, 48, has called home for more than half his life. Two girls who were holding on to a puppy and clinging to a wooden board swept past, far too fast for Klein and other onlookers to go down and grab hold of them. After being told by authorities to go back, Klein returned a couple of hours later, shocked that the floodwaters had almost entirely receded and aghast at the destruction that was left behind. “It was amazing how quick it came and how quick it left,” Klein said. Klein said …