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
Donald Trump has blamed 'radical Islamic terrorism' for UK's 13% rise in crime.
Theresa May said she is "ambitious and positive" for a Brexit deal as EU leaders gave the go ahead for preparations for second phase talks.
Merseyside Police have launched an investigation after crowd trouble at Goodison Park - during which a fan appeared to attack a player.