What We Know About the Weekend Storm Damage in the Midwest, South and East

It collapsed a theater in Illinois. Tossed cars in Little Rock, Ark. Flattened homes in Tennessee. And left thousands without power in New Jersey.

The storm system that tore through the Midwest, South and Mid-Atlantic on Friday and Saturday carved a path of destruction that encompassed an area from Wisconsin to Delaware, south to Mississippi, killing at least 30 people in seven states. Scores more people were injured, and communities were left reeling on Sunday, as they assessed the damage and continued cleanup efforts.

Here is what we know about the storms and their impact.

Was the storm system unusual from a weather perspective?

It is not uncommon to see powerful storms make their way across the middle of the country in the spring, according to Colby Pope, a meteorologist with the National Weather Service in Little Rock, Ark. But the number of tornadoes that this storm produced was unusual, he said.

Trained spotters reported nearly 100 locations where tornadoes were spotted or had caused damage Friday and Saturday, according to the Weather Service. The exact number of individual tornadoes might not be known for days. A storm system producing “20 to 30 tornadoes is pretty common,” Mr. Pope said. But the total for this storm, spread across multiple states, was “a cut above” what meteorologists considered a normal outbreak, he added.

John Allen, associate professor of meteorology at Central Michigan University, cautioned that the final count of actual tornadoes is often far lower than the initial estimate: One tornado could be tracked multiple times in different areas. He said that he expected the total to be in the mid-50s, a figure that he said might emerge every year or two. “Overall, I’d say that it’s not outlandish to see one of these events in the spring,” he said.

To Jake Sojda, a meteorologist for AccuWeather, the storm system was out of the ordinary because it had “two bull’s-eyes,” one farther north centered on Illinois, and another that focused on Arkansas. “Usually, you have the greatest risk really concentrated in one area,” he said. “To have two separate areas that had such a significant risk for tornadoes — that is definitely more uncommon.”

However, the reach of this storm system was far from the most extreme. For comparison, Mr. Pope pointed to the record-breaking 2011 super outbreak of tornadoes. Over a four-day period that April, a storm spawned hundreds of tornadoes across more than a dozen states, killing more than 300 people. One of the tornadoes grew to 1.5 miles wide and traveled more than 80 miles, ripping its way across Alabama and destroying huge swaths of Tuscaloosa and Birmingham, he said.

Although scientists have drawn links between climate change and other weather phenomena like hurricanes, heat waves and droughts, they have not established a clear relationship between a warming planet and tornadoes. But they say climate change may be playing a role in making some tornado-spawning storms more powerful.

Little Rock was the most populated area that was hit.

Arkansas’s capital, a city of about 205,000 people, saw extensive property damage, particularly on the west side of Little Rock in areas filled with businesses and apartment buildings. The tornado sheared off roofs, shattered storefronts, downed power lines and upended cars.

Billy Roehrenbeck, owner of Pulaski County Title Co., a three-story brick building in Little Rock, said 50 employees huddled in a bathroom behind the elevator bank at the front of the building, as the tornado tore through. “The only things that are not touched are the steel, the slab and the glass in the back,” he said.

On Sunday, President Biden declared Little Rock a major disaster area, freeing federal funding to support local recovery efforts.

The storm injured dozens of people, but as of Sunday the city had not reported a fatality. One person was killed in the storm in North Little Rock, a city just across the Arkansas River.

Wynne, Ark., located about an hour west of Memphis, reported at least four deaths. While some areas of Wynne remained largely untouched by the tornado, homes in an area known as Ward IV were severely damaged or even leveled, and many were left without power or water. Neighbors said they had excavated one woman from the rubble of her house after she tried to wait out the storm with her family. And power supply companies from three states came to help the battered area.

Tennessee has suffered the most deaths from the storm.

At least 13 people in the state have died as a result of the storm, according to the authorities.

In McNairy County alone, seven victims were initially reported on Saturday. Two more victims were discovered after volunteers and officials conducted door-to-door welfare checks. At least 72 homes were destroyed, McNairy County’s mayor, Larry Smith, said.

Gov. Bill Lee was among the officials who went to Adamsville, in McNairy County, early Saturday evening. They climbed over fallen trees and branches and walked through the muck of mud and debris, as they surveyed the damage and talked with residents. There are 26,000 people in the county, which is roughly 110 miles east of Memphis.

Nell Daniel, a 97-year-old who lives alone and is hard of hearing, was watching television in her home in Adamsville when the storm came through Friday at around 9:30 p.m. She could not hear the tornado siren or what the meteorologist was saying on her television. But she saw the lightning and read the words on her screen: “Take Cover Now!”

Ms. Daniel grabbed her cane and made it to the bathroom. She shut the door and sat down on the toilet, while the tornado tore off the roof and burst windows in other parts of the house. About a mile away, Ms. Daniel’s granddaughter Robyn Pettigrew frantically tried to get to her grandmother’s house.

With streets clogged with emergency vehicles and debris, she was not able to get to Ms. Daniel until around 4 in the morning. Ms. Pettigrew learned from a neighbor that she had taken Ms. Daniel into her home.

On Saturday, relatives and friends came over to salvage what they could. Every room in the house was wrecked, except for two: the kitchen and the bathroom where Ms. Daniel had sought shelter.

In Illinois, a collapsed theater led to a frantic rescue effort.

In Belvidere, Ill., a city of about 25,000 people that sits less than 90 miles from both Chicago and Milwaukee, the storm caused a “full roof collapse” at the historic Apollo Theater, killing at least one person and injuring 40 people during a metal band concert Friday night.

When the roof came down, the downtown theater went dark, debris flew and concertgoers screamed. Then began a scramble to rescue people under the rubble.

“I didn’t know what happened,” said Gabriel Salas, 45, who was among the attendees. “But I just felt like I needed to help.” Mr. Salas and others followed the sounds of screaming. They dug through rubble and pulled out any bodies they could.

Boone County Emergency’s managing director, Dan Zaccard, credited concertgoers’ efforts. “They acted quickly to remove debris from people,” he said. “There was an effort from concertgoers and bystanders to help each other, and that did help us a lot.”

The outcome could have been much worse. Shawn Schadle, the city’s fire chief, said that there had been 260 people inside the building; that its front awning had also collapsed; and that emergency workers had dealt with gas leaks, an electrical fire behind the venue, and an elevator rescue around the same time.

The storm affected more than a dozen states.

Fatalities were reported in Alabama, Arkansas, Delaware, Illinois, Indiana, Mississippi and Tennessee.

On Sunday, more than 240,000 customers were without power from Arkansas to New York, according to PowerOutage.us. Pennsylvania, where more than 75,000 customers were without power, appeared to bear the brunt of the outages.

In areas where there were no tornadoes, powerful wind gusts caused damage in Ohio, Pennsylvania, Missouri, New York, Georgia, Virginia and New Jersey. The National Weather Service received several reports of wind damage on Saturday, including a tree that fell on a house in Steuben County, N.Y.

In the north, on the cold side of the storm system, snow blanketed cities with several inches of snow, including Oakdale, Minn., where the National Weather Service said more than 12 inches of snow were recorded. The storm also led to power outages in the state, and on Sunday nearly 10,000 customers were without electricity in the Twin Cities area.

The same system also caused high winds in Oklahoma on Friday, prompting what the Weather Service described as a “dangerous wildfire outbreak” in northern and central portions of the state. Nearly 100 fires broke out, destroying more than 40 homes and burning thousands of acres.

Another dangerous storm system is expected this week.

This next storm system, forecast for Tuesday, could bring the potential for a “few strong tornadoes,” large hail and damaging wind gusts from Texas to Illinois, the National Weather Service’s Storm Prediction Center said.

There are two areas of concern for that day: One stretches from northeast Texas through Arkansas and into southern Missouri, and another takes in northern Missouri, southeast Iowa and much of Illinois.

In these regions, where more than 18 million people live, the center said that the risk of severe weather was “enhanced,” the third-highest category on a five-level risk scale.

Marc Chenard, a National Weather Service meteorologist, said that the risks from the storms on Tuesday signal similarities to the storm system that tore through several of the same states on Friday and Saturday.

Gwen Moritz, Jessica Jaglois, Bob Chiarito, Farrah Anderson, Mitch Smith, Neelam Bohra, Winston Choi-Schagrin, Raymond Zhong, John Keefe, Mike Ives, McKenna Oxenden, Eduardo Medina, Joshua Needelman and Claire Fahy contributed reporting.