The Cayuga County Sheriff's Office is investigating a barn fire at the Cayuga County Fairgrounds hours after a big event brought thousands of people to the Weedsport venue.

Authorities are investigating the cause of the structure fire, and don't know if there is a connection between the blaze and the KRockathon. The 911 call came in at 2:45 a.m. Sunday.

The sheriff's office has labeled the blaze's cause as “undetermined/suspicious.” The structure had no electrical services in the apparent place of origin and there were no items that could accidentally start a fire there, investigators said. The flames likely started at the east end of the building, which was completely destroyed, investigators said. There were no animals in the horse barn and it contained little equipment.

Investigators are seeking information on a woman seen taking photographs shortly after the blaze began. The potential female witness is blonde and drove a pick-up truck.

Detectives ask anyone with information to call 253-1610.