At first it sounded to Alec Clark like thousands of hammers hitting the metal roof of the factory all at once. The building began to move, sway almost, as the sound grew louder. Then, in what seemed like an instant, Clark felt the wall behind him move, shoving him and two co-workers across the floor and wrapping itself around them in a tight embrace.

Clark, a 21-year-old maintenance worker at the Mayfield Consumer Products candle factory, was midway through his shift when what authorities believe was the deadliest tornado in Kentucky’s history barreled into his workplace.

The candle factory, one of the major employers in Mayfield, was flattened, reduced to a vast pile of concrete and metal wreckage, studded with overturned cars and leaking vats of hazardous chemicals, the roughly 110 men and women on Clark’s shift trapped inside.

Kentucky’s governor on Saturday said the factory devastation probably would “end up being the largest loss of life in any tornado event in a single location ... in the state’s history.”

Mayfield is a small town, and southwestern Kentucky occasionally sees tornadoes from which Clark had periodically taken shelter as a youth. His parents had lived in the same house a two-minute drive from the candle factory his whole life. But he had never seen a tornado.

As the storm approached and sirens warned of impending danger, the factory workers took cover in the designated storm shelter: a hallway in the center of the sprawling one-story facility, the place farthest from exterior walls that might come crashing inward during a storm.

Several miles away in rural Wingo, Ky., Clark’s fiancee, Logan Miller, sheltered with her siblings and parents in a backroom of the family’s house, their television tuned to local news. As Miller watched the tornado’s path on the screen, she began to panic.

Shortly after 9 p.m., the family realized that the tornado had struck the factory where Clark was working, Miller’s mother Andrea Dowdy said. Miller, who was tracking Clark’s phone, saw that it wasn’t moving.

Dowdy turned to her husband. “Get there now,” she said. “Cause Alec, he’s there, he’s not responding.”

Her husband, son and daughter jumped into the car.

Clark found himself crunched on his side, his knees to his chest. His two co-workers had landed on their stomachs, their legs pinned by heavy shards of the ceiling or wall.

The three men had shut themselves into Clark’s supervisor’s office shortly before the tornado struck. There were more than a hundred others who had taken shelter in the hallway, and Clark could hear them.

“For the first 20 minutes after the building fell, you couldn’t hear anything from the outside, just screaming,” he said. “From hundreds of people: screaming.”

Clark had worked at the factory for about eight months. He liked his co-workers and had made friends there. He tried to comfort the two men at his side who were starting to panic, both in pain and unable to free their legs. He had a flashlight, and could see that they were stuck in a tight pocket of the rubble. About a foot above their heads was more concrete.

His phone pinged, and with his free hand he reached into his pocket. It was a text message that Miller had sent him shortly before the tornado struck. “It’s coming right for y’all, take shelter,” it said.

Clark called her, and the call surprisingly went through. He called his supervisor, whose office he was in. He told them where he was. They were on their way to find him.

Dowdy arrived at the factory soon after her husband and children.

“And the only thing that you can really describe of the whole thing was: It was a big debris field. There was no building. Nothing that resembled that plant,” she said.

There was no telling whether another tornado might be on its way. Kentucky officials would say the next day that the massive storm that struck the factory was one of 30 to touch down in the state overnight.

But at the rubble pile, the Dowdys, first responders, Clark’s father and others with friends and family below got to work in the blustery darkness, struggling against driving rain to reach those whose voices they could hear crying out from beneath the debris.

Some ran to gather tools and equipment. They sawed through metal beams and used the tractors from a dealership nearby to push through rubble. Soon they were pulling people from the wreckage.

There were men and women with horrific crush injuries from concrete walls, beams and cylindrical blocks that had fallen across them, Dowdy said. She saw workers emerge with severe burns from the chemicals that Dowdy said are used to create the candle fragrances at the factory. There were people with severe fractures, people in shock and people with concussions who couldn’t seem to remember their own names, she said.

Dowdy took down the names of survivors as they emerged, so families could be notified. But whenever she glanced around to take in the scene, she saw others whom rescuers had pulled limp from the debris and were performing CPR on. It was heartbreaking, she said.

“There are things that everyone saw last night and we saw today that will be with us the rest of our lives,” Dowdy said later, her voice breaking.

Dowdy’s husband, Daniel Dowdy, and others forged a tunnel through the debris to reach some people, at times with the help of the borrowed tractors, she said. Dowdy recalled seeing one man who approached each survivor pulled from the wreckage to ask, with desperation, whether they had seen his daughter, who he said had been at the facility. Eventually, Dowdy said, the woman was removed, carried out on a stretcher because she had a broken foot.

“That’s my daughter!” the man cried.

Beneath the rubble, Clark began to fear that his co-workers would not make it out. They had stopped screaming, and one, who had a heart condition, was breathing heavily. Clark had used his phone to call their wives, and the men were able to say “I love you,” to them, Clark said.

They could hear people walking on the rubble above them, and Clark worried that their narrow crevice might cave in. He braced his arm periodically against the concrete above. Nearly four hours had passed, but it felt like four days.

Finally, Clark heard muffled voices. “Alec! Alec! Alec!” He called back. Sometime later, a door was hoisted out of the way, and a flashlight beamed in. A voice declared: “Man, am I glad to see you!” It was a family friend, Alan Webb.

Clark couldn’t believe it. The rescuers helped pry the 21-year-old loose, and he crawled out to a landscape of flashing emergency lights, a sort of assembly line of rescuers on a vast hill of debris, and the anxious faces of his family and friends.

He told them about the two co-workers trapped in the spot from which he had been freed, and about the man he could hear through concrete, praying in Spanish over the past few hours, somewhere on the other side of a wall.

He saw his fiancee and fell into her arms, tears streaming down his face. He was bruised and limping, but otherwise unharmed.

Clark said he later learned he had been buried beneath about 15 feet of debris. An hour after local officials had sent Clark, his father, the Dowdys and other civilian rescuers home, he learned that rescue workers had pulled his two friends from the rubble. They were alive, with severe leg injuries, but conscious. And they were on their way to a hospital.

It was about 3 a.m. Saturday. Authorities later said they last pulled someone alive from the wreckage at 3:30 a.m.

Beshear told reporters on Saturday afternoon - roughly 12 hours after that last person was pulled out alive - that rescue work was continuing, but that having seen the site, he was not optimistic. “It’ll be a miracle if anyone else is found alive in it,” Beshear said.

Clark by Saturday evening had realized that there were men and women - friends - he would never see again, people who would not get to go home to their fiancees and spouses the way he had been so lucky to do.

He reckoned that had he not been able to reach his loved ones by phone, and that had they not mobilized to find him, he might not have gotten out at all. The men with him surely would have died, he thought.

“I wish I could do more,” he said, thinking about those who weren’t as lucky. “I felt powerless in that building. I couldn’t move to help the two guys lying beside me.”

“You would think, in a house fire, you have the ability to do something: Get out or try to grab someone. But in this case, it felt like I was tied down to the floor. I couldn’t move, I couldn’t help nobody,” Clark said. “All I could do was tell them ‘they’re coming.’ “