Two windows plunged from separate buildings within half an hour yesterday, highlighting worries about the potentially fatal threat of poorly maintained windows. A third window was prevented from falling by an 80-year-old woman who clung to it until help arrived. No one was injured yesterday, but falling windows killed two people last year, prompting a government publicity campaign on the need for window maintenance. In a chilling replay of the television advertisements, a window in an 11th-floor unit in King's Road, Quarry Bay, crashed into an alleyway when loosened during cleaning by an elderly tenant at 9.30am. Half an hour later a window fell from a vacant second-floor flat onto Temple Street, Yau Ma Tei. In the third incident, also in Yau Ma Tei, a metre-high aluminium window in the 80-year-old woman's bedroom in Shanghai Street was blown loose about 11.30am. The woman hung on to the dangling window for several minutes until her son arrived to help. Police said the problems had been caused by lack of maintenance. Two elderly people were killed by falling windows in Yau Ma Tei and Kennedy Town on January 17 and 20 last year and a teenager was seriously hurt in a similar incident in Tai Po in 2001.