A third person has died of Legionnaires' disease following the outbreak in Cumbria.
Morecambe Bay Hospitals NHS Trust have not named the victim but say she is in her 50s. She was admitted to Furness General Hospital in Barrow last week.
Her death follows that of Wendy Millburn, 56, and Richard Macaulay, 88, both from Barrow.
The source of the outbreak is believed to be the council-run Forum 28 Arts Centre in the centre of the coastal town.
Tests on a 30-year-old air conditioning system found traces of the Legionella bacteria, which causes the disease, in the water treatment plant. A council worker has been suspended.
More than 60 people remain in hospital undergoing treatment.
The condition of three people remain a "cause for concern", said a hospital spokesman.
PA