Lunenburg Ma firefighters arrived to find smoke showing from the eaves of this single family dwelling. Companies discovered heavy fire in the rear attic of the dwelling and command struck a 2nd alarm bringing in mutual aid to the scene and to cover. Due to the amount of fire and areas needed to be overhauled, command struck a 3rd alarm. Companies had the fire knocked down a short time later and remained on scene overhauling and checking for extension.