At least 13 people were killed and dozens more injured as storms tore through Texas, Missouri, Arkansas and Mississippi, spawning tornadoes and floods that left a trail of devastation.
Tornadoes tore roofs off homes, ripped trees out of the ground and tossed cars around "like toys," one witness said. Floods swept cars off the road and downed trees and power lines that flattened homes.
"Close to 80 million are at risk of severe weather today stretching from Georgia up through New England. The biggest impact from these storms will be damaging winds and hail with the risk of isolated tornadoes throughout the day," said CNN meteorologist Michael Guy.
The area includes Baltimore, Washington D.C., Pittsburgh, Buffalo and Greensboro.
The weekend's storm system also generated the risk of downstream river flooding in portions of the central United States.
"Many areas from Louisiana up toward Missouri and into Illinois saw rainfall totals over 7 inches (with some localized amounts up to a foot) fall within 48 hours. Currently there are 21 million under a flood watch or warning from eastern Oklahoma up into Indiana," Guy said.
The National Weather Service said flood warnings would likely be extended in parts of Oklahoma, northern Arkansas, Missouri, Illinois and Indiana, where major to record flooding would continue.
"Many of the rivers in these states have crested or (are) nearing crest and remain in moderate or major flood category. Many roads across this region are closed because of the flooding," it said.
Severe weather damage in Canton, Texas.
The death toll rose to 13 Sunday after a toddler died in Tennessee.
"A 2-year-old girl has died after being struck by a heavy metal soccer goal that blew over in high winds at 2310 Antioch Pike," Metro Nashville Police Department said in a tweet.
"Victim Melanie Espinoza Rodriguez (was) transported to Vanderbilt Children's Hospital where she was pronounced dead," the police department said.
Children missing after car swept away
In Arkansas, emergency workers were searching for two children -- a 4 year old and an 18 month old -- after the car they were traveling in with their mother was swept off the road in Hindsville, Madison County, Saturday afternoon.
"The mother attempted to save the children and herself but became separated by the fast current, when they exited the vehicle.
"The mother was found downstream from the vehicle, and was treated by EMS, but refused transport to the hospital, while the search for the children continued," the Madison County Sheriff's Department said in a statement.
It said the vehicle was recovered without the children and the search was paused after dark for safety reasons.
State of emergency
Arkansas Gov. Asa Hutchinson declared a state of emergency in response to the flooding Sunday. The Arkansas Department of Emergency Management said at least four people had died in the storms.
One woman was killed when a tree fell on a mobile home in De Witt, about 80 miles east of Little Rock, ADEM spokeswoman Whitney Green said.
In Carroll County, the body of a 24-year-old woman was found in a creek. Officials in Washington County reported that a water rescue turned into a recovery without giving more detail on the victim.
Another death in Cleborne County was included in the ADEM's death toll. The agency did not provide further details, but the Cleborne County Sheriff's Office said on its Facebook page that Fire Chief Doug Deckard died "in a tragic accident" while checking an area during a thunderstorm.
The agency did not include in its count the death of a 10-year-old girl in Springdale. The girl and her brother climbed a fence near a creek and the girl was swept away by rushing waters, Springdale Police said in a Facebook post. Her brother was safe and the girl's body was found around midnight, police said.
In Texas, 'heartbreaking' devastation
At least four tornadoes touched down in northeast Texas on Saturday, leaving widespread damage in Van Zandt and Henderson counties, a rural area about 60 miles east of Dallas.
One tornado was approximately a mile wide, the National Weather Service said.
At least four were killed and 49 people were hurt, Canton Mayor Lou Ann Everett said. One person is still unaccounted for. First responders from across the state went door to door Sunday to look for survivors in more than 5,000 homes in the tornado's path, she said.
"It is heartbreaking and upsetting, to say the least," the mayor said.
Canton High School, which was used as a triage center, would be closed Monday, along with the rest of schools in Canton and Fruitvale, Everett said. A curfew is in effect in affected regions outside the city of Canton.
Texas Gov. Gregg Abbott visited Canton on Sunday to survey the damage. He commended local officials and first responders for their work and called on Texans to donate money instead of supplies.
"We saw the the tornado drop out of the sky," said Fort Worth resident Cliff Henthorn, who was in Canton for the event. "This was crazy. It completely looks like a can opener opened this truck right in front of me. "
Fort Worth's Cliff Henthorn took this photo after Saturday's tornadoes in Canton, Texas.
The tornado hit about a mile from 17-year-old Hayley Herron's house. The next day everyone was still in shock, she said.
"The damages were horrible," she said. "Power lines and fences torn down over the roads, my friends' homes destroyed, there were buildings completely gone. Trees were split and thrown across pastures."
Officials in Mississippi blamed the weather for at least two deaths. In Rankin County, a child died from an electric shock in floodwater. Authorities did not provide information on the other death.
Missouri governor: 'Stay home. Stay safe'
At least two people died in the storms that began Friday in Missouri, bringing heavy rain and flooding.
A couple was left stranded in their car when flood waters began to rise in Christian County, officials said. Despite the man's efforts to rescue his wife, their car was swept away with the 72-year-old woman inside. The woman's body was found Saturday in a field near Clever, Missouri.
A second death was reported Sunday, though information about the circumstances was not immediately available.
A total of 111 evacuations and 136 water rescues were reported as of Sunday, Gov. Eric Greitens said.
"Our outstanding first responders are working to protect life and