Rush-hour commuters looked on in horror as Sofyen Belamouadden was chased across a concourse at Victoria station in London by 20 youths charging at him with weapons including a samurai sword.
The schoolboy tumbled down a flight of stairs into an Underground ticket hall where he was surrounded, punched, kicked, and knifed repeatedly as he lay helpless on the floor.
Obi Nwoke, 18, and a 17-year-old youth were convicted of murder and three others found guilty of manslaughter by an Old Bailey jury.
One member of the gang, Samuel Roberts, told the court that he joined in the violence - captured on CCTV - simply because 'everyone else was doing it'.
The 'merciless' attack took just seconds, during which Sofyen was stabbed nine times with such ferocity that one blow cut through his heart and into his spine.
Mark Heywood QC, prosecuting, said: 'He was given no chance of life. So brazen and confident were his killers that they openly carried the various weapons that they used with them as they ran towards him and together hunted him down.'
The violence in March last year was the result of 'simmering tensions' between pupils from two west London schools, the court heard.
Sofyen, from Acton, west London, was targeted in revenge for a boy being given a bloody nose during a skirmish at the station the day before. Read More