Montreal police say that this marks the 11th homicide in the city this year.
The young woman was pronounced dead early this morning at the hospital.
SPVM Media Relations
Another woman, 36-years-old, is still in hospital and is considered "an important witness" in this case.
Police found the young girl and the woman at 3 a.m. early Thursday morning after responding to a distress call.
There are no further details at the moment. Investigators are still at the scene.