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Lee Christensen
A 17-year-old boy has been stabbed to death outside a Tube station in south-west London.
Police found the injured teenager outside Clapham South station in Balham Hill, Wandsworth, after being called at about 16:35 GMT.
The Met Police said the boy was taken to hospital where he died shortly afterwards from his injuries.
Officers have cordoned off the road and pavement around the Tube station, which has been closed.
There have been no arrests, the Met said.
Charity director Robin Pritchard, 47, said he saw the victim lying on the ground in a "pool of blood" as someone gave him CPR.
"It was strangely calm and quiet. I think everyone was in shock," he added.
Police said the boy's next-of-kin have not yet been informed and he is yet to be formally identified. A post-mortem will be held later.
The victim is the second teenager to be knifed to death in London within the last 24 hours.
Jai Sewell, 15, died on Thursday night after being stabbed in a south-east London chicken shop.
Meanwhile, two men were stabbed during a fight between kitchen workers at Sony Music's headquarters in central London.