At least 25 people were killed and dozens remain missing in Tennessee after America's deadliest tornado outbreak in nearly seven years. There were 19 people killed in Putnam County, six were neighbors on the same block.

The victims include 4-year-old Hattie Collins, whose parents Matt and Macy survived. Josh and Erin Kimberlin also died alongside their 2-year-old, Sawyer, when their house was decimated.

Officials said many Tennesseans were asleep in their beds when the system hit overnight between Monday and Tuesday. Cookeville in Putnam County, just east of Nashville, was among the most devastated areas with 18 of the two dozen fatalities.

One Cookeville resident, Seth Wells, told CBS News about how he had been woken up at 1:50 a.m. with a tornado warning on his phone and described hearing a "deep roar" before rushing to take cover with his partner, Danielle Theophile, in their bathtub.

"We were flying in the air, into the trees back there, where once we hit those trees, the house... it just exploded. The house just disintegrated," Wells said.

Theophile said she could feel herself "lifting and flipping over" while their house flew through the air. "I have no clue how we survived," Wells said. "Like 'Wizard of Oz.'"

Theophile said she needed 15 stitches when her forehead was "split open" during the intense ordeal.

As they pick up the pieces and attempt to rebuild their life, Wells said the couple won't "let go" of each other. "Not after this. Not ever. We're not letting go."