Officials said Tuesday that the weekend flooding in Tennessee that killed at least 21 people was even more destructive than previously believed, with the degree of devastation coming into sharper focus as water receded and rescue teams searched for survivors. “Our damage is much more massive than what we thought,” Humphreys County Sheriff Chris Davis told NPR in an interview, saying over 100 homes had been washed off foundations or destroyed—a far larger number than previously estimated. “Yesterday we thought it was 20-something houses that had been removed from the foundations,” Davis said. “That’s not even close. Well over 100-120 houses have been moved, or are gone, no longer exist.” Around a dozen people are believed still missing in hardest-hit Humphreys County, where rescuers with trained dogs continued to scour the area in hopes of finding people still alive. Waverly resident Brittney McCord’s 2-year-old son was washed away in Saturday’s …