Maria Molina has been reporting live all morning amid the devastation in Mayflower, Arkansas, located about 25 miles north of Little Rock. Tornadoes ripped through the area Sunday night, leaving at least 16 people dead in the state. At least two more deaths have been reported in Oklahoma and Iowa from other tornadoes.

** 2:00p ET UPDATE: Officials in Arkansas lowered the death toll to 14 in the state, saying two victims were counted twice. **

Powerful storms are expected to continue today. The graphic below shows the area of Mississippi, Alabama and Tennessee that is under the greatest threat for damaging tornadoes.

Watch Maria's report from the scene, and footage of the huge twister above.

Watch Maria's report above, and read more on the destruction from FoxNews.com:

At least 18 people were killed Sunday by three separate tornadoes spawned by a powerful storm system that moved through the central and southern United States. 

The Arkansas Department of Emergency Management confirmed early Monday that at least sixteen people had died after a tornado tore through central Arkansas, while an Oklahoma county sheriff's dispatcher reported that one person had died in the town of Quapaw, near the state's borders with Kansas and Missouri. Fox News has also confirmed that one person died when a tornado hit Keokuk County, Iowa.

The Arkansas tornado touched down about 10 miles west of Little Rock at around 7 p.m. local time and moved northeastward for at least 30 miles, the National Weather Service reported. It missed the state capital but passed through or near several of its suburbs, causing widespread damage in the communities of Mayflower and Vilonia.

According to the Arkansas Department of Emergency Management, ten of the deaths occurred in Faulkner County, where Mayflower and Vilonia are located. Five more occurred in Pulaski County, and one occurred in White County.

The tornado, which grew to be a half-mile wide, turned buildings into rubble and stripped the leaves and smaller branches off of trees.

"There's just really nothing there anymore. We're probably going to have to start all over again," Vilonia Schools Superintendent Frank Mitchell said early Monday after surveying what had been a $14 million intermediate school set to open this fall. Because the tornado struck after nightfall, the full extent of the damage would be impossible to asses until after sunrise Monday.

The twister shredded cars, trucks and 18-wheelers stuck along Interstate 40 north of Little Rock. After the storm passed, tractor-trailer rigs tried to navigate through the damage to continue their journeys, while gawkers held smartphones to their windows to offer a grim glimpse of the destruction.

State troopers went vehicle-to-vehicle to check on motorists and said with genuine surprise that no one was killed.

"About 30 vehicles -- large trucks, sedans, pickup trucks -- were going through there when the funnel cloud passed over," said Bill Sadler, a spokesman for the Arkansas State Police.

Karla Ault, a Vilonia High School volleyball coach, said she sheltered in the school gymnasium as the storm approached. After it passed, her husband told her their home was gone -- reduced to the slab on which it had sat.

"I'm just kind of numb. It's just shock that you lost everything. You don't understand everything you have until you realize that all I've got now is just what I have on," Ault said.

 The National Weather Service in North Little Rock said it was virtually certain that the Mayflower and Vilonia storm would be rated as the nation's strongest twister to date this year.

"It has the potential to be EF3 or greater," said meteorologist Jeff Hood. EF3 storms have winds greater than 136 mph. "Based on some of the footage we've seen from Mayflower and where it crossed Interstate 40, things were wrecked in a very significant way."

From communities west of Little Rock to others well north of the capital, emergency workers and volunteers were going door-to-door checking for victims.

"It turned pitch black," said Mark Ausbrooks, who was at his parents' home in Mayflower when the storm arrived. "I ran and got pillows to put over our heads and ... all hell broke loose."

"My parents' home, it's gone completely," he said.

Becky Naylor, of Mayflower, said she and her family went to their storm cellar after hearing that tornado debris was falling in nearby Morgan. Naylor, 57, said there were between 20 and 22 people in the cellar and they were "packed like sardines."

"Everyone is welcome to come into it," she said. "In fact, people were pulling off the highways and were just running in."

She said the men held the cellar doors shut while the tornado's winds tried to rip them open.

"It sounded like a constant rolling, roaring sound," she said. "Trees were really bending and the light poles were actually shaking and moving. That's before we shut the door and we've only shut the door to the storm cellar two times."

The White House issued a statement in which President Barack Obama promised that the federal government would help in the recovery and praised the heroic efforts of first-responders and neighbors.

"Your country will be there to help you recover and rebuild as long as it takes," Obama said.

The Arkansas tornado was one of several that touched down Sunday as a large storm system moved through parts of the Plains, Midwest and South.