Officials With Holston Army Ammunition Plant In Kingsport Say They May Never Know The Exact Cause Of A Fire And Explosion At The Facility In 2019. They Say The Fire Started Inside A Staging Building, Spread To The Roof, Causing An Overhang To Fall Onto A Trailer Containing 25-Hundred Pounds Of Explosives. The Company Said There Were No Witnesses To The Incident And There Is Just Too Much Destruction From The Explosion To Determine The Exact Cause Of The Fire.