Tornado outbreak live updates: 40 dead in cross-country storm system

At least six people have died in Mississippi in the outbreak of tornadoes Saturday, the governor said.

Another three people are missing and 29 people are injured, Gov. Tate Reeves said in a social media post Saturday night.

"Please pray for those who lost their life, those who are missing and those leading the search efforts, those who are healing, and their families," Reeves said in the post.

Three of the deaths -- including of a juvenile -- were in Tylertown, not far from the Louisiana state line, according to Tylertown Police Chief Jordan Hill.

The governor signed a state of emergency declaration that he said will allow the state to further mobilize state resources. Overall, 21 counties sustained storm damage and about 16,000 are without power, the governor said.

The deaths in Mississippi brings the total death toll from an outbreak of severe storms over the past day to 34 people as of Saturday evening.

The thing that is often most striking in the aftermath of a tornado is the path of the storm — it's often so clear, so distinct.

The same held true on Baker Street in tiny Villa Ridge, Missouri, about 40 miles west of St. Louis. When the deadly storm system rumbled over the bi-state area, the tiny hamlet of around 3,000 people was hit hard. A reported tornado cut through more than a dozen homes, leveling the second floors of each while entirely sparing homes on either side of its brutal tear through this area.

Entire walls blown off, offering an unexpected glimpse into people’s bedrooms. A TV hung on a wall above some family pictures, bottles of cologne somehow still standing on the armoire below. A child’s bedroom, books still on the shelves but with no ceiling or walls around it.

There were no reported deaths in the town.

Neighbors said everyone walked away with moderate injuries at the worst. They’d know, too. It’s a close-knit area. By Saturday, people were already out with bobcats and chainsaws, clearing away the massive trees and branches littering the area.

So it goes in "Tornado Alley." Some are spared, some are not. And everyone knows there’s always a chance it can happen again.

-ABC News' Matt Rivers

Over the past 24 hours, more than 40 reported tornadoes have swept across eight states in the Midwest and South -- and the dangerous severe weather threat continues.

The eight states with reported tornadoes in the past day are Alabama, Missouri, Arkansas, Mississippi, Louisiana, Illinois, Indiana and Tennessee.

Overall, there have been more than 500 reports of severe weather since late Friday, from the Midwest into the South, including not only tornadoes, but damaging wind gusts and large hail.

Across the South, Tornado watches remain in effect in portions of Mississippi, Alabama, Louisiana, Tennessee and Georgia as a line of powerful storms continues to sweep east.

A tornado watch designated a "Particularly Dangerous Situation" remains in effect for much of Alabama and portions of Mississippi and Louisiana until 8 p.m. CT. The worst of the tornado threat will be over after this.

From eastern Tennessee, including Knoxville, into northwestern Georgia, a tornado watch remains in effect until 1 a.m. ET. Additional watches could be posted in the coming hours for points east, across George and into the Florida Panhandle.

There is also the threat of additional severe thunderstorms bringing potentially damaging wind gusts and large hail. Any stronger, slow-moving thunderstorms could also bring torrential rain and frequent lightning.

Dangerous flash flooding is also a concern. Flash flood warnings are in effect from southern Mississippi through central Tennessee.

-ABC News' Daniel Peck

Gov. Sarah Huckabee Sanders addressed reporters Saturday, saying the devastation in Arkansas could take weeks and months to recover from.

Three people have died in the storm so far, she said.

The governor encouraged residents to document impacts to their homes and said officials were working to get power running again in the affected areas.

She said it may take weeks and months to recover. The biggest challenges will be clearing the debris and getting food and water to people in need.

-Victoria Arancio