Eighteen people are missing after a blast at a military explosives manufacturing facility in Tennessee on Friday.
Humphreys County Sheriff Chris Davis said one person initially believed to be on site had been located at home. Four or five people were taken to a nearby hospital after the enormous explosion that levelled the factory.
There's nothing to describe, it's gone, he said.
The plant in Bucksnort, Tennessee - roughly 56 miles (90km) south west of Nashville - specializes in the development, manufacture, handling and storage of explosives. The cause of the blast remains unclear.
Aerial video from the scene showed charred debris, smouldering vehicles and little remaining of the facility, which is owned by Accurate Energetic Systems.
Sheriff Davis, who was visibly emotional during his first media briefing of the day, declined to say exactly how many people died.
However, he noted that the plant had been operational when the explosion occurred, and that secondary blasts forced first responders to maintain a distance from the site.
Workers who had just begun their shifts now may be missing or deceased. A lot of times, when I have these types of situations, I refer to them more than just a person...we're missing 19 souls, Davis stated.
During a second briefing hours later, Davis confirmed that 19 people were still unaccounted for and that the explosion happened in a large building, flinging debris across a half square mile.
This was a massive enough explosion that I can tell you that folks in Waverly felt and heard this explosion, he said, referring to a town about 15.5 miles (25km) northwest of the facility.
Davis declined to specify whether he believed the explosion was accidental or intentional, stating, we have to make the worst assumption in order to find the truth.
Tennessee Governor Bill Lee noted in a social media post that his office was monitoring the unfolding situation, calling it a tragic incident. State and local authorities are cooperating with federal agencies in response to the explosion.
The factory, which sat on about 1300 acres of land, produced C-4, TNT, and other high-grade military and commercial explosives.
Accurate Energetics Systems has now ceased operations, and the company reportedly employed around 75 people.
They are focusing on their families, their employees, Davis mentioned.
The explosion took place on the border of Hickman and Humphreys Counties, prompting a massive response from local and federal agencies, including the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
The agencies have secured the scene and declared it stable, with officers expected to remain on site for several days to investigate the incident thoroughly.
Another blast occurred at the same location in 2014, causing one fatality and three injuries at the time.
Ken Cross, former President of the Institute of Explosives Engineers, emphasized the dangers associated with explosives manufacturing, stating: Mixing explosives and filling munitions is a high hazard, low probability industry when properly regulated.
Media reports indicate that residents over 20 miles from the site felt the explosion that shook the facility.
