LONDON, ENGLAND - AUGUST 04: Police officers stand guard by flowers left at the scene of a knife attack in Russell Square on August 4, 2016 in London, England. Six people were attacked by a 19 year old man with a knife at 10.30pm in Russell Square, London last night. A woman died of her injuries. The suspect was arrested at the scene and is being held at a London Hospital. Police say mental health issues are a significant factor. (Photo by Jack Taylor/Getty Images)
