(CNN) -- A barn fire that killed two men and dozens of horses in Ohio on Saturday shows no sign of criminal intent, authorities said.
The Ohio State Fire Marshal said the cause of the fire, at the Lebanon Raceway near Cincinnati in southwestern Ohio, is undetermined.
"However, investigators have ruled out criminal intent," it said in a written statement.
The ages and identities of the men are not yet known. Initially, officials reported that 65 horses perished, but later put the number at 43.
The state fire marshal said that preliminary information from the men's autopsies may be available by Sunday.
The fire began in the northwest corner of the barn, according to the state fire marshal's office. It would not release the specific origin of the fire because of the investigation.
The Warren County Fair Board -- which operates the track -- confirmed the men's deaths and the destruction of the barn, but couldn't say how many horses were killed. It said in a statement that harness racing scheduled for Saturday night has been canceled.
Firefighters from 11 departments, which received the call just before 5 a.m., cleared debris and extinguished hot spots during the day.
For more than 50 years, the Warren County Fair Board has been operating the county fair grounds, which includes "a harness racing track and supporting facilities that are leased for harness racing meets to two harness racing clubs," according to the statement issued by a fair board attorney, Bill Schroeder.
Schroeder said the fire was first noticed by a neighbor and that the barn, harness-racing carriages, and other racing equipment have been destroyed.
Firefighters kept the flames from spreading to other barns, officials told CNN affiliate WHIO-TV. State and local fire officials are working to determine what sparked the fire.
Another barn fire at the fairgrounds killed 35 horses in 1988, Warren County Commissioner Pat South said, according to the Springfield (Ohio) News-Sun newspaper.