Reed Arnold was watching TV on Saturday at his home in Clarksville, Tenn., when he saw a warning on his phone. He stepped outside and filmed the swiftly moving clouds and a looming tornado. Minutes later, the twister hit his neighborhood.

“One second you are sitting in your house, and all of a sudden, all this carnage happens,” he said.

A sober mood gripped Clarksville and other communities in Middle Tennessee on Sunday as crews searched for survivors and officials surveyed the damage from severe storms and tornadoes that killed at least six people in the region and injured more than 60.

The storms and tornadoes, part of a broader stretch of severe weather that swept across the South on Saturday, left a swath of destruction that included parts of Clarksville, near the Kentucky border, where three people died, and communities around Nashville, where three others were killed.

On Sunday, Clarksville, Nashville and other Tennessee cities and towns were working to clear away debris from a landscape where pink installation clung to tree limbs, children’s toys lay crumpled and flags had been shredded to ribbons.