One person was killed and three were injured Wednesday in an explosion and fire at an ammunition plant in Tennessee.

Rescue workers were called to the blast site about 3:45 p.m. Wednesday, said Michael Knight, a spokesman from the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Rodney Edwards arrived at Vanderbilt University Medical Center about 5 p.m. Wednesday and died later that evening, a hospital spokesman said. Joey Clark, another worker, was listed in critical condition. A woman, who was not identified, was in stable condition, and another man was already discharged.

Knight said a National Response Team would be arriving at the Rio Ammunition plant in McEwen on Thursday afternoon to investigate the incident. The NRT will work with state and local officials to reconstruct the accident scene, identify the origin of the blast and fire, conduct interviews, and collect evidence from the debris.

Humphreys County Emergency Management Agency director Odell Poyner said about 20 employees were believed to be in the building when the blast occurred. The explosion blew out two walls and a significant part of the roof, he said. The fire also ignited brush fires in a nearby forested area, but all had been extinguished by Wednesday night.

Criminal activity is not suspected, but investigators said they would be looking at all possibilities for the cause of the incident.

Rio Ammunition manufactures hunting and target loads for law enforcement and civilian use. Rio’s parent company, MAXAM, also supplies civil, military and sparking markets with ammunition, according to information listed on their website.

The plant explosion attorneys at Schechter, Shaffer & Harris, L.L.P., Accident & Injury Lawyers  provide legal assistance to workers injured in industrial accidents across the nation.