on 29 january 2010, no. 45j ma tau wai road, ma tau wai, a five-storey tong lau of more than 50 years history, suddenly collapsed at approximately 1:43 pm. four people were killed. such spontaneous, cascading and complete building collapse in hong kong has been quite rare since the second world war and the incident raised concern of the hksar government and the hong kong public towards the safety of the aging "tong lau" in hong kong, especially those built with similar specifications 50 or more years ago.