Police are flying two people down to Plymouth to be with a young woman who was found 'seriously ill' in a Mutley property.
Police say they were called after a concern for welfare in the Mutley Plain area and gained entry to the multi-occupancy property at 9:50am today.
The teenager, believed to be aged 19 or 20, was found by police in a serious condition after suffering what they described as a medical episode.
Paramedics and police performed CPR on her and she was taken to Derriford Hospital by ambulance.
In a multi-agency operation two of the woman's next of kin are being transported to Derriford Hospital to be by the woman's side.
One relative from the London area was escorted courtesy of British Transport Police down to Plymouth by train.
Another, from the Cheshire area, is being flown to the Avon and Somerset region by Cheshire's force helicopter.
They will then be driven to Plymouth by a roads policing unit.
A police spokesman said: "The young lady was found to be seriously ill and is now in a critical condition in hospital.
"Cheshire police force, British Transport Police and Devon & Cornwall Police are all involved in arranging transport for the next of kin to be with the young lady."
Police say there are no suspicious circumstances surrounding the woman's condition.