Investigators determine a fire early Sunday at a Lawrence property rental office was intentionally set.The fire broke out just after midnight Sunday at Jayhawk Property Management. Fire Chief Mark Bradford stopped short of calling the fire arson — saying more needs to be known about the reason the fire was set before making that ruling. Bradford would not reveal details about whether the fire was set inside our outside the building — or what was used to ignite the blaze — which caused an estimated 45-thousand dollars in damage to the structure and its contents.