Investigators have ruled that fires at horse barns at the Kentucky Exposition Center were the result of arson.

A small fire in one barn caused little damage Monday afternoon but a second one early Tuesday morning destroyed four barns and damaged four others.

State, local and federal investigators concluded Thursday that both fires were deliberately set.

The Kentucky Division of Fire Prevention, the state fire marshal, Louisville Fire & Rescue arson investigators and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives are all cooperating in the continuing investigation of the fairgrounds fires.

"The fires were definitely set," Maj. Henry Ott, head of the Louisville arson squad, said Thursday. "We all agree on that."

Ott said the two fires in two different barns about 12 hours apart led investigators to conclude arson as the cause.

"It was not a case of the wind blowing (sparks or embers) from one barn to the other. And we eliminated electrical problems as a cause."

He said the person or persons who set the fires could be charged with second-degree arson, a Class B felony punishable by 10 to 20 years in prison.

No one was injured in the fires, the first of which occurred the day after the Kentucky State Fair ended and was doused by fairgrounds employees. Dozens of top saddlebred horses were stabled in the fairgrounds barns through Saturday for the World’s Championship Horse Show during the fair, but none were there when the fires occurred.

Ott said an ATF dog, a black lab named William that was trained in detecting accelerants, helped determine where the fires may have started and pinpointed areas from which evidence was taken and sent to laboratories for testing.

Ott said the materials included sawdust and some burned wooden portions of the structures. He said it may take a month or more to get results. The barns, built after the 1974 tornado, had wooden frames and wooden roofs with asphalt shingles.

Ott said investigators will now begin conducting followup interviews, including with exposition center employees, to try to identify who may have set the fire.

None of the fairgrounds barns has sprinklers and they are not required by state regulators, Ott said. He noted, however, that Churchill Downs has sprinklers in all of its barns and he said that sprinklers would probably have contained the damage to the fairgrounds barns "to a real small area."

Harold Workman, president of the Kentucky State Fair Board, estimated the damage to the barns at more than $1 million. He said the barns didn’t have sprinklers when built in 1974 because codes didn’t require them and, since then, "we have not gone back and looked at it." But including sprinklers in at least the four barns to be rebuilt "is definitely something we will consider," he said.

Workman said he has asked the state Finance and Administration Cabinet for emergency funds to rebuild the four destroyed barns. He said insurance should pay for most of the cost of replacing the barns.

Workman said the fairgrounds still has 16 usable barns, including the four that sustained minimal fire damage — mainly charred columns and some roof damage. Each of the 16 barns can stable about 50 horses.

Workman said the barns used primarily wood chips for bedding. The wood chips probably helped feed the large fire once it started, Ott said.

Workman said construction of new barns, once under way, should take about two months. He said he doubted if new barns could be in place for the North American International Livestock Expo, Nov. 6-20, which includes both a quarter horse and a draft horse show. He said the horse shows may be able to be staged without major problems, if the organizers can carefully schedule when horses arrive at and depart the fairgrounds.

Anyone with information about the fire is asked to call the state’s arson hotline at (800) 272-7766.