Fire crews are fighting a fire at a building on Whiting Street in New Britain on Monday afternoon. The fire is at the New Britain Heat Treating Corporation. Since there's oil in the building, firefighters are fighting the flames with fire suppression foam and are using a defensive operation. Officials are also concerned that the roof of the building may collapse. According to fire officials, the fire started shortly before 4 p.m. It is unclear if the building was occupied when the fire began. The Connecticut Department of Energy and Environmental Protection has been notified and is heading to the scene.