Firefighters on Wednesday were battling a three-alarm fire inside the Brookside Terrace Apartments in Newton. Crews said they were met with heavy fire on the 10th floor of the building, which is located on Mill Street in Newton. Part of Mill Street was closed as firefighters from several companies fought the fire, according to police. It was not clear whether there were injuries in the blaze, which was reported shortly after 7 a.m.