On Thursday 27th March 2003 the decision had been made to stop all clinical teaching and all non-elective patient care at the Prince Philip Dental Hospital, the teaching hospital of the Faculty of Dentistry of the University of Hong Kong. A lethal respiratory disease of unknown aetiology was spreading through the community but also in medical hospitals where it was infecting healthcare workers with apparent ease. Infections in an apartment block called Amoy Gardens seemed to have taken place by the deadly long distance airborne transmission route. The daily numbers of new cases of Severe Acute Respiratory Syndrome were rising exponentially. Normally bustling streets and public buildings of Hong Kong had fallen silent.