Authorities say no one was working at the Halifax Fertilizer Co. in Enfield when the fire started Friday night.
Enfield fire Chief Ronny Locke says the 18,000 square-foot plant was completely destroyed.
Locke said it will take several days for authorities to figure out what caused the fire. Authorities say the fire may have started in the shop and moved to the warehouse.
Enfield police Chief Eddie Buffaloe says some homes were briefly evacuated but that the fire and any runoff posed no immediate threat to the plant's neighbors.