Parents of an apprentice carpenter who was stabbed to death fear knife crime is "out of control" in the capital.
Jason Isaacs, 18, was critically injured in Northolt last Saturday when he was chased by moped-riding attackers.
The QPR fan had been travelling to a party with friends before he became separated from the group.
He was then stabbed multiple times and, despite being taken to hospital, died from his injuries on Tuesday.
Scotland Yard have issued a £20,000 reward for information relating to his death.
Mr Isaacs' family have now described his death as "senseless" and pleaded for a clamp-down on knife crime.
A statement from Mr Isaacs' family described him as a "beautiful son and brother".
He enjoyed music, fashion, football and was a "very popular" boy, according to a statement.
His family said: "We feel that knife crime in this area, and in London, is out of control and it must be stopped before another young life is taken, and another family has to suffer what we are suffering now.
"We need to educate young people early on around the dangers of carrying knives in public places.
"We are pleading with the public to come forward and assist police in their enquiries to find out who murdered our son as we are currently living in a nightmare; our family is incomplete without Jason and will never be the same again."
Investigators believe Mr Isaacs and his friends were chased by two mopeds with pillion passengers wearing balaclavas.
The attack appeared to be "unprovoked" and "pre-planned".
Detective Chief Inspector Noel McHugh said: "Jason was a popular lad who has had his life brutally ended for no reason, leaving his family and friends devastated.
"We will do everything we can to track down his killers who acted in a truly horrific manner."
A 17-year-old boy was arrested on November 20 and later bailed.
Anyone with information concerning this attack is asked to call police on 020 8785 8099 or via 101. You can also call Crimestoppers anonymously on 0800 555 111. You can also tweet information to police via @MetCC.