- Investigators continue to probe a massive explosion at a Tennessee explosives plant.
- The blast killed 16 people and registered as a 1.6 magnitude earthquake.
- Authorities are using DNA tests and cell phone data to identify victims and causes.
NASHVILLE — Nearly three days after a massive blast at a Tennessee facility that specialized in making military explosives, investigators are still combing through the site where 16 people were killed in a "mass detonation" so significant it produced seismic readings hundreds of miles away, experts say.
Investigators from multiple agencies, including the FBI, are assisting in the response to recover remains for DNA testing, which will likely span days, officials have said. No one has been found alive during the complex search, according to Humphreys County Sheriff Chris Davis. The cause of the explosion remains under investigation, authorities said.
Meanwhile, residents are undergoing a "gauntlet of emotions," Davis said, as Friday's blast brought painful memories of tragedies that traumatized the close-knit community and first responders parse through the scene foot by foot.
Here's what we know about the explosion and the investigation:
Sheriff describes scene as 'hell on everybody involved'
The early-morning Friday explosion at Accurate Energetic Systems, a manufacturing plant for military and demolition explosives, was a "devastating blast," Davis said, noting responders were able to secure the site by late morning.
The detonation – which was so large that it registered as a 1.6 magnitude earthquake, according to data from U.S. Geological Survey – left charred debris and mangled vehicles across the area.
The blast set off smaller explosions, local officials said, and shook homes as far as 15 miles away while scattering debris over half a square mile.
Accurate Energetic Systems called the incident at its facility a "tragic accident," in a Friday statement. Davis described the event as one of "the most devastating scenes" he has ever seen.
"It's hell," Davis told reporters Friday evening. "It's hell on us. It's hell on everybody involved."
Law enforcement resources from across Tennessee, including federal agents and the Tennessee Highway Patrol Special Operations Unit, were dispatched to assist in the investigation, a source familiar with the effort told CNN. More than 300 emergency personnel were at the scene Friday, officials said.
The area surrounding the plant is typically patrolled by smaller law enforcement departments, the person said, which has prompted other agencies to volunteer resources for support.
The Hickman County Sheriff's Office, Humphreys County Sheriff's Office and the Bureau of Alcohol Tobacco, Firearms and Explosives are leading the investigation, which is expected "to go on for days," Hickman County Mayor Jim Bates said.
Due to the nature of the explosion, recovery efforts have proven to be excruciating for victims' families and investigators working to clear the area, potentially detonating and recovering any other explosives in the vicinity and using DNA to identify remains, officials have said.
Investigators planned to perform rapid DNA tests on-site "so that we're able to identify individuals and provide those answers to the families waiting for those answers," David Rausch, the director of the Tennessee Bureau of Investigation, said Sunday.
"We're at a snail's pace," Davis said Sunday, adding, "We will work until there is no work left to be done to try and find the answers that need to be found."
The recovery effort was being made "more volatile" with the presence of ordnance at the site, and investigators were working with the FBI to use cellphone technology to figure out what happened at the time of the explosion, Davis said Saturday.
Investigators are also pulling employment records and conducting controlled explosions, a source familiar with the investigation said.
"Every effort is being made to conduct a thorough, methodical and science-based investigation to find the answers that led to this tragedy and the answers that this community deserves," Tyra Cunningham, assistant special agent in charge at the Nashville division of the ATF, said Saturday evening.
The agency will ensure "that if criminal activity is involved, those responsible will be held accountable, and if it was accidental, that lessons have been learned to prevent a tragedy like this from ever happening again," Cunningham said.
Authorities reveal all 16 victims' names
In a Monday news conference, authorities revealed the names of all 16 victims of Friday's tragedy: Jason Adams, Erick Anderson, Billy Baker, Adam Boatman, Christopher Clark, Mindy Clifton, James Cook, Reyna Gillahan, LeTeisha Mays, Jeremy Moore, Melinda Rainey, Melissa Stanford, Trenton Stewart, Rachel Woodall, Steven Wright and Donald Yowell.
"We may not have known that individual personally, but in some form or fashion, we probably, or do, know their family or extended family. And it's this small county, rural America, where everybody knows each other and everybody's only going to take care of each other," Davis said Monday, adding that among the victims was his neighbor's husband and one of his childhood best friends.
Contributing: Dalia Faheid, Hanna Park, Maxime Tamsett and Ray Sanchez
