Of the 25 killed by the twisters, 18 were Putnam County residents, Putnam County Mayor Randy Porter said Wednesday.
Five children under the age of 13 died in Putnam County, Porter said.
The tornadoes touched down Tuesday in the hours after midnight, ripping through Nashville and other cities in Tennessee. The twisters wiped out dozens of homes and businesses, including churches and schools.
Some of those killed were asleep in their beds, officials said.
Wilson County Mayor Randall Hutto told ABC News that a person in the town of Lebanon, who had been found in a damaged facility, died on Wednesday to become the 25th victim of the storm.
"It hit so fast, a lot of folks didn't have time to take shelter," Porter said. "Many of these folks were sleeping."
One apartment complex was "totally demolished," Porter said.
Annakate Ross told ABC News she sheltered with her family in a closet in their Nashville home.
Once the twister moved through, she opened the closet door to find that "the windows were blown out, the doors had been blown open and our neighbor had been ejected from his back house apartment into our yard."
"He survived," Ross said. "He's doing great."
Nashville resident James Duncan said sirens started in the middle of the night before "howling" winds moved in.
"Things started hitting the window, and my girlfriend and I shot out of bed and darted for the bathroom. We could hear objects slamming against the building ... it was terrifying," Duncan told ABC News. "They say tornadoes sound like a train ... they were not lying. The feeling in my head from the pressure was insane. I've never felt anything like it."
Evan Winsor told ABC News he saw lightning hit the telephone pole in his Nashville backyard, knocking out the power. The wind picked up and it started to rain and hail, so he rushed to the basement to take cover.
Winsor said his neighbors were "in disbelief" as they surveyed the toppled telephone poles and rubble in the street.
One neighborhood "totally wiped out" was Five Points, an "iconic cultural hub in Nashville -- especially with the local music and food scene," Winsor said.
The Basement East live music venue was completely destroyed.
The twisters left planes decimated at the John C. Tune Airport in West Nashville. No one there was injured and crews from Nashville International Airport will help rebuild, said Doug Kreulen, Nashville International Airport president and CEO.
Decosta Jenkins, CEO of Nashville Electric Service, called this the "most devastating storm of my career."
About 600 utility poles were broken, Jenkins said. As of Wednesday afternoon about 34,800 customers remained without power.
Tennessee Gov. Bill Lee has declared a state of emergency as a result of the devastation. President Donald Trump said he plans to visit Tennessee on Friday.
The National Guard has been deployed to help with search-and-rescue efforts.
Putnam County Sheriff Eddie Farris said Wednesday that crews still have to comb though about 40% of the rubble.
Despite the destruction, Winsor said the community is pulling together to help each other.
Nashville Mayor John Cooper said the website for Nashville volunteer organization Hands On Nashville crashed three times Tuesday from so many people trying to sign up to volunteer.
Cooper said Google pledged $100,000 and that Amazon is donating supplies to community centers.