Two nearby schools, Mariam Boyd Elementary School and Warren New Tech High School, were closed on Thursday due to smoke damage, according to an assistant fire chief on the scene.
Officials said the blaze began at the Southern States Farm Supply at 216 West Franklin Street around 6 p.m. on Wednesday. The store sells supplies such as hardware and fertilizer and also provides fuel storage.
Authorities say they heard two explosions come from inside the two city block-long building and were concerned about chemicals in the air, so they evacuated 15 to 20 homes in a five block radius. No one was injured.
On Thursday evening, Warrenton Mayor Pro-Tem Woody King lifted the mandatory evacuation. It is now a voluntary evacuation. People may now return to their homes and businesses, even though smoke is expected to remain in the area for several days.
Officials say the fire appeared to have started after hours and the store was entirely engulfed in flames within a short time.
Eyewitnesses at the scene said flames were shooting up out of the building and smoke could be seen for miles.
"It looked like a jet liner crash, I mean it was bad ... the flames were well over the trees," said Milton Cooper. "This is one of the oldest businesses in this town and it's sad to see it go, but thank God no one was hurt."
Cooper, an inspector with the state DMV license and theft bureau, lives in the area and said when the call first came out, he rushed over to help because the area was so confined and the neighborhoods were so close together.
"The chief of police asked all law enforcement and fire personnel if they could get everybody out of their homes because that fire, when I arrived, was encroaching upon the properties back there," Cooper said.
A nearby library was open at the time and was also evacuated. The outside of the building sustained some heat damage.
It took dozens of fire crews from North Carolina and Virginia several hours to battle the blaze. Raleigh's HAZMAT team was also called in to help out.
The cause is still unclear. Town officials say they do not suspect arson, but they have contacted the SBI and have requested their arson investigators to come out.
Warrenton is 55 miles northeast of Raleigh and just south of the Virginia state line.