A 63-year-old woman died from swine flu yesterday, bringing the death toll since late December to 18, the Hospital Authority said. Three of four new swine flu patients are in critical condition - a woman, 63, at Princess Margaret Hospital, a man, 55, at Caritas Medical Centre and a man, 48, at Yan Chai Hospital. A 29-month-old girl is in serious condition at Queen Elizabeth Hospital. Twenty-six people are being treated for swine flu in the city's public hospitals.