WALTHAM, MASS. (WHDH) - Authorities are investigating a fire they say was intentionally set late Wednesday night at a former mental facility, which is currently being used for a holiday light display in Waltham.

Crews responding to a reported fire at the former Walter E. Fernald Developmental Center’s administration building on Trapelo Road just before midnight found flames coming from the back of the building.

One firefighter suffered a minor injury and was treated at the scene before returning to duty, according to Waltham Deputy Fire Chief Roger Hebert.

The fire was intentionally set, causing extensive damage to the basement of the building, Waltham Fire Chief Thomas MacInnis, Waltham Police Chief Keith D. MacPherson, and State Fire Marshal Peter J. Ostroskey said in a joint press release.

Anyone with information is asked to call the Arson Hotline at 1-800-682-9229.

The abandoned building is being used as a drive-through light display this month.

“I believe the city is just trying to get people out because of the whole COVID thing, so they had a nice light display that people could drive through and drive through safe, so they’ve been using the property for that,” Hebert explained. “The city owns that and was letting the Lions Club use it for that.”

Advocates have been calling for the display to be moved, saying the use of the site is “disgraceful” because of the alleged abuse and neglect that happened there to developmentally disabled children.

It is unclear if the alleged arson has any connection to this call to action.

(Copyright (c) 2026 Sunbeam Television. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

Join our Newsletter for the latest news right to your inbox