The former site of the controversial Fernald Center was purposely set on fire in Waltham, Massachusetts, according to authorities.
A holiday light show on the grounds this year stirred up controversy in the city, according to the Boston Globe, sparking protests over the festive display outside a building that once operated as an institution for children with developmental disabilities.
Advocates say children with disabilities were mistreated during the Cold War at the building, the Globe reported, which has been vacant for several years.
On Thursday morning, Waltham Fire Chief Thomas McInnis, Police Chief Keith MacPherson, and State Fire Marshal Peter Ostroskey announced that the fire was "intentionally set," and caused by a "human act."
A firefighter was injured while battling the two-alarm blaze on Trapelo Road, which was reported by site security just before midnight Wednesday. The injury was minor and the firefighter returned to duty after being treated on scene.
Firefighters, unable to access the building, primarily fought the flames from outside. There was extensive damage to the basement level of the building, according to officials.
Anyone with information about how the fire started is asked to call the Arson Hotline at 1-800-682-9229. All calls are confidential, officials noted.
The hotline is part of the Arson Watch Reward Program, which gives up to $5,000 rewards for information that helps solve the cause. The program is funded by the property and casualty insurance underwriting companies of Massachusetts.
Members of the Waltham Fire Department Fire Investigation Unit, Waltham Police detectives and state police assigned to the Office of the State Fire Marshal are investigating the fire.