Sudbury police have arrested several people following a knife fight. During the incident one person was stabbed and was treated for a serious wound. Police say the fight started when a group broke into an apartment with the intent of beating up the occupants. By the time police arrived the fight had spilled onto the street and a 15-year-old girl was waving a knife. They arrested her at gunpoint as well as several others. The 15-year-old is charged with assault with a weapon and weapons dangerous.