Twelve people have been arrested after the London Bridge and Borough Market attack which left seven people dead and 48 injured. Malik Ramadhan is divisional director of emergency care and trauma at the Royal London Hospital, where 12 of the victims were taken. Andrew Thurgood is a consultant nurse in pre-hospital care and works for charity Citizen Aid. They discuss how their staff react to such an attack and what people can do to help and stay safe. (Image: Commuters on London Bridge. Credit: Getty Images)