No survivors found after Tennessee explosives plant blast

No survivors are expected to be found after a major explosion at a Tennessee munitions factory on Friday that has left 18 people unaccounted for.

Recovery teams are still clinging to hope of finding any of the missing alive, but assume the missing are deceased, said Humphreys County Sheriff Chris Davis.

"As we get into this, we find it even more devastating than we thought initially," he told a news conference.

It's still unclear what caused the explosion at the plant in Bucksnort, Tennessee - roughly 56 miles (90km) south-west of Nashville. The facility specialises in the development and manufacture of explosives.

Video footage taken on Friday showed fires still burning, charred vehicles, and smoke rising from the razed building. Officials said debris was scattered for half a mile around where the building once stood.

Accurate Energetic Systems, which runs the plant, has suspended its operations.

More than 300 state and local first responders have been searching the site since Friday morning and have not found any survivors, Sheriff Davis said on Saturday.

"The expectation of anyone who's inside of that building… we can assume that they are deceased," he told media.

By Saturday morning, the rescue mission had shifted to a recovery operation, said Davis, who was visibly choked up.

The FBI is also at the site conducting rapid DNA tests to identify victims and notify families.

"We're trying to focus as much attention as we can, on taking care of their families," Sheriff Jason Craft from neighbouring Hickman County told the BBC.

The Bureau of Alcohol, Tobacco, and Firearms is at the scene helping to investigate the incident.

There was a previous fatal explosion at a unit in the same location in 2014.

Justin Stover, whose property borders Accurate Energetic Systems' sprawling campus told BBC his house shook violently following the explosion.

At first, he thought the loud noise must've been a plane crash, Stover said, adding that he thought his house was going to collapse.

"Things fell off the wall, items fell off shelves," he said. "It was very intimidating, like the loudest thunder you've ever heard in your life and rumble."

Then, he could see "a large cloud of smoke coming from the area of AES," Stover said.

He is still assessing damage to his house and said the explosion may have affected his water well.

Stover, who has lived in Bucksnort for 20 years, said AES had about 80 workers.

"It's one of the only businesses in this area. So it's one of the only places for employment, for locals. There's a lot of people that we know that work there and that possibly lost their lives yesterday morning."

The tragedy will be devastating for the whole community, he said, as it already has been for the families of the victims.

Residents further away from the site also heard the blast, including some in a town about 15 miles (25km) away, Sheriff Davis said on Friday.

One local resident who lives about 20 minutes away from the facility told the BBC she was sitting at her daughter's dining table when she heard it.

"All of a sudden we just a heard a loud bang. We didn't know if it was a gun or what," she said.

Another local resident, Lucy Garton, who has lived nearby for six years, didn't hear the explosion herself but she experienced the aftermath as she was on her way from work on Friday.

"When I came home, the roads were just blocked with state troopers. You had to show up proof that you lived here to get through," she said. "There was a lot of ambulances, fire trucks, everything, parked down at the gas station."

She said her husband knows people who worked in the facility.

"I think it will definitely impact the area," she said. "It's a very close-knit community and everyone, they're just simple people, go to work every day, take care of their families and just real a family-oriented community."

She said a lot of people in the area are employed at the plant, adding, "I'm sure it'll be hard for them to go back to work after such a tragedy."