A teenager who filmed another boy throwing a chair from the top of an east London shopping centre - narrowly missing shoppers - has admitted recklessly causing a public nuisance. The pair were arrested after a viral video showed the chair plunging to the ground from a height at Westfield in Stratford, as part of an internet prank in March last year. The boy who threw the chair previously admitted criminal damage and recklessly causing a public nuisance, and was sentenced to an eight-month detention and training order, the Crown Prosecution Service (CPS) said. The other youth, 15, admitted the charges at Stratford Magistrates' Court on Monday and he is due to be sentenced on 29 April. The footage showed a hooded youth throwing a two and a half stone (15kg) blue chair over a glass balustrade before he and the boy filming the act run away swearing in the opposite direction. It was posted online accompanied by the words "No way bro almost killed someone", the court heard.…