The Georgia Emergency Management Agency also reported a new death in Douglas County west of Atlanta, bringing the toll in that county to four people. No more details were immediately available.
The victims included a toddler swept away from his family when a swollen creek ripped apart their trailer home in west Georgia on Monday. Many others were drivers whose vehicles were pushed off roads by rapidly rising waters. One man in Chattanooga, Tenn., was missing two days after betting onlookers he could swim across a flooded ditch next to his house.
Authorities urged people who don't need to drive to stay home, a day after Gov. Sonny Purdue declared a state of emergency in 17 counties.
"It's going to be a long morning. We're asking people to be patient," DOT spokeswoman Crystal Paulk-Buchanan said.
The good news was that the rain was tapering off in many areas. The National Weather Service said there was more rain to come, but the likelihood and severity will decline in the coming days.
Days of downpours and thunderstorms saturated the ground from Alabama through Georgia into eastern Tennessee and western North Carolina, just months after an epic two-year drought in the region ended after winter rains.
As Tuesday rush-hour began in the Atlanta area, Interstate 20 west of the city was closed in two spots by water spilling over the major artery for commuter traffic from the sprawling western suburbs. Portions of at least two other interstates in the metro area were also closed, as was I-75 in Houston County in central Georgia.
Hundreds of roads and bridges were under water or washed out in the Atlanta area and other parts of the state, including 17 bridges on state and interstate highways.
Dozens of roads remained closed in western North Carolina and several small landslides were reported. Officials said the flooding there was the worst since remnants of hurricanes Frances and Ivan came through in 2004.
As much as a foot of rain fell over parts of the Atlanta area Monday. The town of Dallas northwest of Atlanta had 16 inches in a 48-hour period, the Georgia Emergency Management Agency said.
Aerial shots showed schools, football fields, used car lots and even entire neighborhoods submerged by the deluge, sending some unlucky residents scurrying for higher ground.
"It's a mess all over," said Lisa Janak of the Georgia Emergency Management Agency.
As the storm front rumbled through west Georgia, it turned a normally sleepy creek into a surging headwater that tore apart 2-year-old Preston Slade Crawford's mobile home around 2 a.m. Monday. The body of the drowned boy nicknamed "Scooter" wasn't found until hours later. His parents had been rescued from the raging waters as another son, Cooper, age 1, clung to his mother's arms in Carroll County, west of Atlanta.
Pat Crawford, the boy's grandmother, watched helplessly as the family's mobile home was whisked away.
"Y'all gotta help us! Y'all gotta save us!" Crawford remembers Bridgett Lawrence and Craig Crawford shouting above the roaring water. She said she was on higher ground, but couldn't get to them because the current was so bad.
About 12,000 Georgia Power customers were without power late Monday.
Crews in the tiny Georgia town of Trion worked to shore up a levee breached by the Chattooga River and in danger of failing. The town evacuated more than 1,500 residents, and Red Cross workers set up an emergency shelter.
Emergency officials were often forced to improvise to rescue dozens of people stranded in their homes and cars.
"We're using everything we can get our hands on," Douglas County spokesman Wes Tallon said. "Everything from boats to Jet Skis to ropes to ladders."
Other southeastern states were hit less severely.
In Kentucky, rescue crews went on more than a dozen runs to help stranded people after 4 inches of rain fell on parts of Louisville on Sunday, said city fire department spokesman Sgt. Salvador Melendez.
Water rose as high as window-level on some houses in North Carolina's Polk County, forcing emergency officials to evacuate homes along a seven-mile stretch of road. Flooding in more than 20 counties in western North Carolina closed roads, delayed school and forced evacuations.