Caroline Eggers

The company is called Accurate Energetic Systems.

According to its website, AES produces several types of explosives, including TNT, or trinitrotoluene.

But officials involved in the investigation have not disclosed what type of explosives were in the building.

During a press conference, Agent Tyra Cunningham of the Bureau of Alcohol, Tobacco, Firearms, and Explosives said more verification was needed.

TNT is one of the most common explosives used by the military.

The company also produces a component of C4.

For NPR News, I'm Caroline Eggers in Nashville.

The Friday morning blast was powerful.

Vibrations were recorded hundreds of miles away from the small Tennessee town.

There's little left of the factory building, but chemical clues were splattered across the blast zone.

Tennessee Governor Bill Lee says the investigation will likely take months.

Lee said it's still a live scene.

Technicians are looking for explosive material, and after the site has been secured, they'll begin to look into the cause of the explosion.

For NPR News, I'm Caroline Eggers in Nashville.