WYNNE, ARK. -- Residents across a wide swath of the U.S. raced Sunday to assess the destruction from fierce storms that spawned possibly dozens of tornadoes from the South and the Midwest into the Northeast, killing at least 29 people.

The storms tore a path through the Arkansas capital and also collapsed the roof of a packed concert venue in Illinois, stunning people throughout the region with the scope of the damage.

"While we are still assessing the full extent of the damage, we know families across America are mourning the loss of loved ones, desperately waiting for news of others fighting for their lives, and sorting through the rubble of their homes and businesses," President Joe Biden said in a statement.

Biden earlier declared broad areas of the country major disaster areas, making federal resources and financial aid available to support recovery.

Gov. Sarah Huckabee Sanders in Arkansas, where at least five people were killed, already had declared a state of emergency and activated the National Guard.

Confirmed or suspected tornadoes in 11 states destroyed homes and businesses, splintered trees and laid waste to neighbourhoods.

The National Weather Service confirmed Sunday that a tornado was responsible for damage to several homes near Bridgeville, Delaware. One person was found dead inside a house heavily damaged by the storm Saturday night, Delaware State Police reported.

It may take days to confirm all the recent tornadoes and where they touched down. The dead also included at least nine in one Tennessee county, five in Indiana and four in Illinois.

Other deaths from the storms that hit Friday night into Saturday were reported in Alabama and Mississippi.

Residents of Wynne, Arkansas, a community of about 8,000 people 50 miles (80 kilometres) west of Memphis, Tennessee, woke Saturday to find the high school's roof shredded and its windows blown out. At least four people died.

Ashley Macmillan said she, her husband and their children huddled with their dogs in a small bathroom as a tornado passed, "praying and saying goodbye to each other, because we thought we were dead." A falling tree seriously damaged their home, but they got out unhurt.

Chainsaws buzzed, as bulldozers plowed into debris. Utility crews restored power as some neighbourhoods began recovery.

Nine people died in Tennessee's McNairy County, east of Memphis, according to Patrick Sheehan, director the Tennessee Emergency Management Agency.

Tennessee Gov. Bill Lee drove to the county Saturday to tour the destruction and comfort residents. He said the storm capped the "worst" week of his time as governor, coming days after a school shooting in Nashville that killed six people including a family friend whose funeral he and his wife attended earlier in the day.

"It's terrible what has happened in this community, this county, this state," Lee said. "But it looks like your community has done what Tennessean communities do, and that is rally and respond."

Jeffrey Day said he called his daughter after seeing on the news that their community of Adamsville was being hit. Huddled in a closet with her 2-year-old son as the storm passed over, she answered the phone screaming.

"She kept asking me, `What do I do, daddy?"' Day said, tearing up. "I didn't know what to say."

After the storm passed, his daughter crawled out of her destroyed home and drove to nearby family.

In Memphis, police spokesman Christopher Williams said via email late Saturday that there were three apparent weather-related deaths there: two children and an adult who died when a tree fell on a house.

Tennessee officials warned that a repeat of similar weather conditions is expected Tuesday.

Illinois Gov. J.B. Pritzker traveled Sunday to Belvidere to visit the Apollo Theatre, which partially collapsed as about 260 people were attending a heavy metal concert.

Frederick Livingston, Jr., was pulled from the rubble but didn't survive. He had gone to enjoy the concert with his son, Alex.

"I couldn't save him," his son told WLS-TV. The father and son were standing side by side when debris began raining down. "It happened so fast."

The governor said 48 others were treated in hospitals, with five in critical condition.

Pritzker also planned to visit Crawford County, about 230 miles (370 kilometres) south of Chicago, where three people were killed and eight injured when a tornado hit around New Hebron.

"We've had emergency crews digging people out of their basements because the house is collapsed on top of them, but luckily they had that safe space to go to," Sheriff Bill Rutan said at a news conference.

That tornado was not far from where three people died in Indiana's Sullivan County, about 95 miles (150 kilometres) southwest of Indianapolis. Several people were rescued overnight, with reports of as many as 12 people injured.

In the Little Rock area, at least one person was killed and more than 50 were hurt, some critically. The National Weather Service said that tornado was a high-end EF3 twister with up to 165 mph (265 km/h) winds and a path as long as 25 miles (40 kilometres).

Masoud Shahed-Ghaznavi was having lunch at home when the tornado roared through his neighborhood. He hid in the laundry room as sheetrock fell and windows shattered. When he emerged, the house was mostly rubble.

"Everything around me is sky," he recalled Saturday.

Another suspected tornado killed a woman in northern Alabama's Madison County, officials said, and in northern Mississippi's Pontotoc County, authorities confirmed one death and four injuries.

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DeMillo reported from Little Rock. Associated Press writers around the country contributed to this report, including Kimberlee Kruesi in Adamsville, Tennessee, Harm Venhuizen in Belvidere, Illinois, Corey Williams in Detroit, and Ron Todt in Philadelphia.