A Metropolitan Police spokesman said the teenager died at about 11.10pm.
Police said there was no clear motive for the shootings yet and no-one has been arrested.
At this very early stage we must retain an open mind regarding the circumstances of the incident and any motive.
Detectives from Trident are leading the inquiry and an incident room will open in the morning.
Witnesses to the shooting or anyone with information about the incident are asked to call police on 101 or Crimestoppers on 0800 555 111.
More top news
Stephen Fry has quit Instagram, telling fans he has been "hounded off" the social media site.
The Office star Martin Freeman has given his backing to Labour in the party's first party election broadcast in England.
Today's weather will remain unsettled, with some cold, wet and windy conditions.