"Mind the Gap" - three little words that most Londoners barely notice anymore.
But for Margaret McCollum that simple instruction on the underground has a very personal meaning. It was the voice of her late husband Oswald Lawrence.
Robyn Dwyer explains:
More top news
London Ambulance Service has more paramedic job vacancies than anywhere else in England.
Hundreds of people march for more affordable homes and control private rents in London.
Police proposals suggest that all frontline police officers should have the option of arming themselves with Tasers.