It could be days before investigators know what caused the fire that destroyed Grimes Mill.

The structure, built in 1896, caught fire Wednesday night and continued to smolder throughout the day Thursday.

The mill produced feed and flour products and was operational until 1982. The Historic Salisbury Foundation owns the mill, located on North Church Street.

Flames were visible for miles Wednesday night as bystanders looked on while the historic structure burned.

A preliminary investigation began Wednesday night. But officials weren’t able to get inside the building until the fire was completely out, said Salisbury Fire Chief Bob Parnell.

The core of the fire continued to reignite hours after it began, making attempts to extinguish the blaze difficult.

“The weather today and forecasted weather tonight will certainly hinder or at least slow down the actual outside activities of investigating,” Parnell said Thursday moring during a press conference.

The bigger hindrance is the stability of the building, he said.

Fire crews never went inside the structure. No injuries were reported.

“It was heavily involved. We activated a defensive mode of operation,” Parnell said.

Firefighters poured water on the fire from the ground and from above using a ladder truck.

Parnell estimated fire crews flooded the fire with 6,000 to 7,000 gallons of water a minute. He estimates at the height of the fire, 125 firefighters were on the scene. Firefighters from as far as Kannapolis joined Wednesday’s efforts to extinguish the five-alarm fire.

Many off-duty firefighters returned to work to help out.

“I’m very happy with the response that we got. Our mutual aid was outstanding,” Parnell said.

He said the fire was under control in three hours and crews spent the rest of the night and much of Thursday putting out hot spots.

The fire progressed quite rapidly, Parnell said, because the building had no sprinkler system.

A second floor back wall collapsed Thursday, and other walls began to fall inward throughout the day.

Multiple agencies are working together to investigate the fire, including the Salisbury Fire Department, Salisbury Police, the city Fire Marshal’s Office, SBI and agents with the Bureau of Alcohol, Tobacco, Firearms and Explosives.

On Thursday, around 2:45 p.m., an ATF agent was finally able to get close enough to take pictures of the remains.

Parnell said ATF had offered to help in the investigation.

Fire officials called the SBI, Parnell said, because of the size of the building and type of occupancy.

Volunteers were inside the building Wednesday, said Mary James, a member of the Historic Foundation’s board of trustees.

James and her family left their South Fulton Street home late Wednesday and watched as flames poured out of the building.

Her family was drawn to Salisbury eight years ago for the “historical aspect” the town offered.

“There are people like us who are attracted to towns that have an historical character,” she said.

James, who returned Thursday morning with her husband, Will, said it was heartbreaking watching the fire consume the building.

“Naturally I have an even keener interest in the buidling,” she said.

Not only is James on the board, but she’s attended fund-raisers and other events at the mill.

“The loss of all of that is just sad for us,” she said.

Volunteers were in the building Wednesday evening, painting and cleaning. They left around 4:30 p.m., James said.

Volunteers were preparing the mill to be used as a local educational tool.

“Those of us who believe in historical preservation, it’s nice to appreciate your past and appreciate old structures, and how they contribute to your life today. And so as an educational tool and a piece of history that was a treasure for this town — that’s where I think the loss is, and also the hard work so many people put into it,” she said.

The mill contained some antique furniture and some original benches from the Salisbury Depot. There were also clothes and other donated items.

Buddy Petrea heard about the fire on the morning news. He and his wife drove to the site to see for themselves.

As a child, Petrea recalled bringing wheat to be ground into flour to the mill. He brought his now adult children to the mill to have their corn ground for cow feed.

Petrea and his wife have a print they bought from Salisbury artist Betty Sedberry of the mill. He is grateful they have the print because it means so much more now.

Contact reporter Shavonne Potts at 704-797-4253.