BURLINGTON (AP) -- Vermont fire investigators say a floor of a vacant building in Burlington was vandalized, resulting in more than $40,000 in damages. One firefighter suffered a minor injury.

Investigators say firefighters responding to an alarm Thursday discovered the third floor had been vandalized and a small fire set had been set. The fire had been extinguished by a sprinkler head.

Burlington police arrived with K-9 teams but no one was located. Burlington Police, Burlington Fire Marshal’s Office and the Vermont State Police Fire Investigation Unit will be looking into the case.

Investigators are asking anyone with information to call the Arson Tip Line at 1-800-32-ARSON. Up to $5,000 is offered for information leading to an arrest.