Fitchburg firefighters battled a stubborn fire in a 4 story brick apartment building in the early morning on 1/5/25. Companies arrived to find smoke showing from the building and located an apartment fire on the 4th floor. Command struck a 2nd alarm bringing in mutual aid to the scene. The fire extended into some void spaces and command struck a 3rd alarm. The fire was knocked down a short time later and companies remained on scene overhauling and checking for extension.