Firefighters from multiple communities are battling a blaze at old the Fernald School in Waltham. Around 10:30 a.m., Cambridge Fire announced they are assisting the Waltham Fire Department with a third-alarm fire aqt the Fernald School on Trapelo Road.

Shortly after 10:30 a.m., the Cambridge Fire Department announced it was assisting the Waltham Fire Department in a mutual aid response for a third-alarm fire at the Fernald School property at 200 Trapelo Road.

Firefighters are battling a blaze at the old Fernald school property in Waltham, Massachusetts, on Saturday. The fire was reported shortly after 10 a.m. at 200 Trapelo Road, the address of the former Fernald State School.