Arson has been determined as the cause of the fire earlier this week that completely destroyed four barns at the Kentucky State Fairgrounds and damaged four others. Public Protection Cabinet spokesperson Dick Brown says investigators learned of another fire that had been extinguished in the area the day before, and detected the use of fire accelerants at the scene.Brown says investigators are now turning their attention to people who work at the fairgrounds – including people who were employed just for the state fair.“Trying to track all those people down has been a little difficult," says Brown, "but they want to finish the interviews, make certain they’ve talked to everyone who may have seen something, may have heard anything, and may know something. That’s the next step in the investigation is to conclude those interviews.”Officials are also looking for help from the public. Brown says the State Fire Marshal’s Office is offering a one-thousand dollar reward for information that leads to an indictment.