The present-day London Ambulance Service was formed in 1965 by the amalgamation of nine existing services in the new county of Greater London, and in 1974, after a reorganisation of the NHS, the LAS was transferred from the control of local government to the South West Thames Regional Health Authority. On 1 April 1996, the LAS left the control of the South West Thames Regional Health Authority and became an NHS trust. In late 2017, LAS adopted the Ambulance Response Programme, which altered the targets for response times to 999 calls to reflect patient outcomes by removing hidden waiting times after a successful trial by the Yorkshire Ambulance Service, West Midlands Ambulance Service and South Western Ambulance Service. Structure As an NHS Trust, the LAS has a Trust Board consisting of 13 members. The board includes; a non-executive chairman, five of the service's executive directors (including the chief executive), and seven non-executive directors. The chief executive and chief ambulance officer have responsibility for oversight of seven directorates: Accident and emergency operations Information Management and Technology Finance People and Organisational Development Medical Patient transport services (PTS) Operations are directed from two control rooms: one in central London and one in east London, both of which have the ability to take over control entirely if required. Special events in London are co-ordinated from the service's event control room, also located in east London. During mass casualty incidents, the command structure works on three (or four) levels: gold, silver and bronze. Platinum command: government level command (COBR) Gold command: strategic command, located in a situation room close to the main Emergency Operations Centre (EOC) and not only managing the incident, but also ensuring that normal service function continues with reduced resources. Silver command: tactical command, from the control room managing the incident; Bronze command: on-site operational commanders managing sectors within the incident. This system was used effectively in response to the 7 July 2005 London bombings. Staff ranks and roles The LAS employs a number of operational staff in different departments Call centres and control rooms In addition to the 999 emergency service, LAS operates 111 urgent care services covering north east and south east London. In the year to March 2020, the service answered and triaged 2.08million 999 calls, 1.22million 111 calls, and attended 1.18million incidents. The 999 and 111 call centres and control rooms employ a total of 1,655 staff. Ambulance