Colleagues mourn the loss of Lau Kam-yung, the second to die at United Christian Hospital Frontline medical staff were thrown into mourning again yesterday as a fourth health-care worker died of Sars after a nearly two-month battle with the disease. Lau Kam-yung, a 47-year-old health-care assistant, contracted the deadly infection on April 2. She had been caring for a patient who had initially not shown Sars symptoms at a medical ward of the United Christian Hospital. Her death came 12 days after that of Tang Heung-may, another health-care assistant at the same public hospital in Kwun Tong. They had cared for the same patient. Within minutes of her death yesterday morning, a memorial corner was set up in the block at the hospital where she had been working. Lau, who was married with two children, came down with the disease on April 2. Eight days later, she was transferred to the intensive-care unit. Her colleagues were bereft, after having struggled to save her. 'We gave her first-line and second-line treatment, including traditional Chinese medicine,' said Liu Shao-haei, a senior manager with the Hospital Authority. Six medics were last night still in intensive care. They include a doctor at Alice Ho Miu Ling Nethersole Hospital and two health-care assistants - one at Tuen Mun Hospital and one at Prince of Wales Hospital. The other three were from the private sector. A further 12 medics were still in hospital as of last night, a spokesman for the Hospital Authority said. Besides Lau, an 80-year-old man died of Sars yesterday at Princess Margaret Hospital, taking the death toll to 269. Two new cases were confirmed, bringing the number so far to 1,728, while a further 12 suspected cases were found. A total of 105 Sars patients remain in hospital, 32 of whom are in intensive care. Meanwhile, officials said last night that environmental contamination might have been the cause of a mini-outbreak at Wing Shiu House in Sha Tin's Lek Yuen Estate. Eleven residents from five units, including a four-month-old baby, fell ill on different occasions last month. The latest to be confirmed with Sars was on May 22. Director of Health Margaret Chan Fung Fu-chun said gene fragments of the coronavirus were found on the floor and windowsills of two flats on the fourth and fifth floors, near the flats of infected tenants. The tenants of flats where the contaminated swabs were taken have so far not shown symptoms of Sars, but were being monitored, she said. Dr Chan said the Sars virus might have been spread by infected tenants who breached quarantine.