A "much-loved" 15-year-old girl died after being stabbed in the neck with a foot-long knife during the morning rush hour, a witness has said.Security worker Victor Asare told the PA news agency that blood ran "like water" and members of the public rushed to help after the girl was attacked in Croydon, south London, on Wednesday.A 17-year-old boy who knew the victim has been arrested.

A "much-loved" 15-year-old girl died after being stabbed in the neck with a foot-long knife during the morning rush hour, a witness has said.Security worker Victor Asare told the PA news agency that blood ran "like water" and members of the public rushed to help after the girl was attacked in Croydon, south London, on Wednesday.A 17-year-old boy who knew the victim has been arrested.