Tornado Left Deadly Path of Destruction up to 250 Miles Long in Six States

In Mayfield, a working-class town of 10,000 people in the state’s southwest, entire city blocks had been razed, with piles of steel beams, splintered wood and insulation remaining where there had once been multistory buildings. The storm had stripped trees of all their branches and thrown cars hundreds of feet from where they had been parked.

Some 110 people had been working at a Mayfield candle factory when the storm hit on Friday night, Mr. Beshear said; just 40 of them had been pulled out alive by Sunday.

“I’m not sure we’re going to see another rescue,” he said. “We’ve been hit in a way that is unimaginable.”

In all, the National Weather Service on Friday received reports of 37 tornadoes across Arkansas, Illinois, Kentucky, Missouri, Mississippi and Tennessee. Though it may take several more days before scientists can officially assign severity rankings to the tornadoes, they said debris might have been hurled as high as 30,000 feet into the air, the cruising altitude of many passenger jets.

One tornado in the cluster plowed a path of devastation up to 250 miles long, according to initial reports. If those are confirmed, scientists said, it may break a record for the longest tornado track set in 1925, when a single tornado traveled 219 miles across portions of Missouri, Illinois and Indiana.

At least 56,000 people in Kentucky are without power, Mr. Beshear said, and houses in many places are missing roofs, doors and windows, with temperatures dropping below freezing. Six warming centers are open across the state.

The storm may also end up as one of the deadliest in U.S. history. In one town of 2,700 people, Mr. Beshear said on NBC’s “Meet the Press” Sunday, the list of residents who were unaccounted for was eight pages long, single spaced.

The rescue efforts, he said, were complicated by the huge expanse of the disaster area.

In Mayfield, as the tornado approached, Kyanna Parsons-Perez and other employees at the Mayfield Consumer Products Candle Factory were evacuated to a hallway near the back of the building. They could hear the wind outside, Ms. Parsons-Perez said, and the lights went out. Someone shouted, “Get down.” Then the building collapsed.

Ms. Parsons-Perez was trapped beneath a water fountain, with an air conditioning unit on top of that. When she called 911, she said, the dispatcher told her that they were trying to get to the people in the factory but it would be difficult. So she began to broadcast on Facebook Live. “I wanted more people to know that we were in there, trapped,” she said. “We needed to get more than just the Mayfield Police and Fire Department out there.”

When rescue workers pulled her out, after three hours in the rubble, she asked them what time it was. They said it was 12:03 a.m. on Saturday. “Then wish me happy birthday,” she told them. She turned 40 on Saturday.

On Sunday, Ms. Parsons-Perez said in an interview, she was sore but uninjured. A single mother of four, she needed a new car—hers had been parked outside the factory and was carried away by the storm. She also needed a new source of income, she said. “They’re not going to say, ‘You ain’t got to pay rent,’ ” she said.

A co-worker who had helped train her was still missing, and hundreds have lost their homes. “There are people who still don’t have anything,” she said, adding that her church would help her.

The Federal Emergency Management Agency’s administrator,

Deanne Criswell,

said on ABC that the agency is “still in the lifesaving and life-sustaining mode,” after which the federal government will look to address the immediate and long-term needs of affected residents.

“Right now, Kentucky is the only state that has asked for and received an emergency declaration,” Ms. Criswell said, though the agency is in contact with state and local authorities in the other affected states. She said she is “providing the president regular updates” on the situation on the ground.

President Biden said Saturday that the string of deadly storms was “likely one of the largest tornado outbreaks in our history.”

In Illinois, at least six people were confirmed dead at an

Amazon.com Inc.

warehouse hit by a tornado in Edwardsville. The city’s fire chief,

James Whiteford,

said Saturday evening that 45 people had made it out alive from the facility and that search operations were continuing.

On Friday, the site received tornado warnings between 8:06 pm and 8:16 pm, and site leaders directed people to immediately take shelter. A tornado formed in the parking lot before striking the building at 8:27 pm, an Amazon spokesperson said Sunday. Workers had sheltered in place at two locations, one of which was hit directly, the spokesperson said.

The building hit by the storm was a delivery station, an Amazon facility that prepares orders for last-mile delivery. The facility employs 190 people across various shifts, though not many people were on shift at the time of the tornado, the spokesperson said. The tornado hit at the end of a shift.

“Our team worked quickly to ensure employees and partners could get to the designated shelter in place area, and we want to thank them for everything they were able to do,” the Amazon spokesperson said.

Amazon founder

Jeff Bezos

tweeted Saturday: “All of Edwardsville should know that the Amazon team is committed to supporting them and will be by their side through this crisis. We extend our fullest gratitude to all the incredible first responders who have worked so tirelessly at the site.”

Fatalities were also reported at a nursing home in Arkansas. In Tennessee four people were killed as of Sunday, state officials said.

Moving forward, Ms. Criswell, the FEMA administrator, said the agency would work with communities to bolster resiliency against increasingly intense storms.

—Robert Lee Hotz, Natalie Andrews and Courtney McBride contributed to this article.

Write to Ian Lovett at ian.lovett@wsj.com