UPDATE:
One confirmed tornado struck a part of the east Mississippi city of Columbus on Saturday afternoon, authorities said.
The tornado hit in a downtown area of the eastern Mississippi city about 5 p.m. Saturday, but details of how long it remained on the ground weren't immediately known, said meteorologist Anna Wolverton with the National Weather Service in Jackson.
There were no immediate reports of any deaths or major damage, though local media reported some power failures.
"Radar confirmed a tornado," Wolverton said by phone, adding a team would head out Sunday to assess its intensity after it hit in the city of about 23,000, not far from the state line with Alabama.
Earlier, a six-mile stretch of the Natchez Trace Parkway was closed in Mississippi after water covered part of the road.
The National Weather Service had issued a flash flood warning for northwestern Lafayette County in Mississippi after emergency officials reported that a local dam was at risk of failing.
Meteorologist Kole Fehling said emergency officials reported the threat involved the Audubon Dam, which blocks a creek on the north side of Oxford, Miss., and a subdivision. Emergency management officials were not immediately available for comment Saturday.
EARLIER:
MEMPHIS — Homes, highways, parks and bridges throughout the South have been flooded or rendered out of commission Saturday, as the toll of days of drenching rains swelled waterways and pooled over saturated lands amid the threat of severe storms.
Interstate 40 near the border of Tennessee and North Carolina was closed due to a rockslide, one of the dozens of roads and highways shut down throughout the South, transportation officials said.
Tennessee Department of Transportation spokesman Mark Nagi said on Twitter that a "full scale detour" was in place, with traffic being diverted to Interstate 81 and Interstate 26.
In Bruce, Miss., rivers broke flood stage and flash floods poured into homes and businesses. WMC-TV reports that a local state of emergency was declared by officials in Grenada, Miss., after dozens of streets and homes flooded.
High water also threatened property in Tennessee, which, like many other areas of the South, has been soaked by several inches of rain over the past week. Officials said a mudslide destroyed a Subway restaurant in Chatanooga, Tenn. No injuries were reported.
The business' owner, Owen Megahee, had closed its doors on Friday at around noon after a tree fell on an employee's car.
"I saw part of the hill trying to come down, so I was like, 'Let's get everybody out of here,'" he said.
Officials with the Chattanooga Fire Department said his decision potentially saved lives.
"If they had it open, and employees and customers had been in there, we'd be talking about something much more serious," Fire Department spokesman Bruce Garner said. "People could have been hurt or killed for sure."
News outlets report that water rescues have been performed in some Middle Tennessee counties. Flash flood warnings and watches remained in place throughout the South.
Weather officials warned residents of the possibility of severe storms Saturday in western Tennessee, northern Mississippi and eastern Arkansas. Damaging winds, tornadoes and large hail were possible, the National Weather Service in Memphis reported.
Kentucky announced Friday that it was closing the U.S. 51 bridge over the Ohio River to Cairo, Ill., because of flooding on the southern approach. The bridge, which carries 4,700 vehicles a day, is likely to stay closed until Thursday, and possibly longer.
The Ohio River at Cairo is predicted to crest Sunday at its third-highest level ever recorded, and stay that high into next week. The Tennessee River near Savannah, Tenn., also is forecast to crest at near-record levels.
In North Carolina, a Catawba County building inspector said extra weight from rain is suspected to have contributed to a partial roof collapse at a child day care center in Hickory. The Hickory Daily Record reported that firefighters responded to a roof collapse at Rainbow Child Care Center on Thursday morning. There were no children at the facility at the time, and no injuries were reported.
The Chattanooga Times Free Press contributed to this story.