This story was first published in The Straits Times on March 15, 2013
HONG KONG - Runaway sales of a humble cooking ingredient were the first sign that something was wrong.
In November 2002, Hong Kongers heard rumours of Guangdong residents snapping up vinegar - its acidic fumes would ward off a mystery illness going around, some said. Few took notice.
Three months later, a doctor from Guangzhou crossed over to Hong Kong to attend a wedding. He checked into Room 911 of the Metropole Hotel in Kowloon. He stayed one night.
During his short stay, Professor Liu Jianlun, 64, would have come into contact with others in the lift or lobby.
One of those was a 26-year-old who had visited a friend in Room 906. Days later, he took ill and was taken to the Prince of Wales Hospital. There, he infected 23 others, including a group of medical students on a study tour.
Another man went to his brother's home at Amoy Garden Block E where, bent-double by diarrhoea, he kept rushing to the toilet. The sewage pipes would transmit the virus vertically through the building, infecting 200 residents and killing 42.
A young tourist from Singapore returned home, where the virus infected 238 people. Thirty-three died.
There were also hotel guests from Vietnam, Canada and Taiwan.
Thus began the spread of a virus, then unnamed but which would cause the disease known as severe acute respiratory syndrome (Sars). Prof Liu, who had been treating patients at a hospital in Guangzhou, died two days after arriving in Hong Kong.
In all, Sars infected 8,096 people worldwide. About 10 per cent - 774 people - perished. Hong Kong was the hardest hit, with 1,755 people infected and 299 deaths.
As Sars spread its tentacles in Hong Kong, a miasma of terror shrouded the former bustling city. What made the situation unbearable for the city's residents was the sheer uncertainty - no one knew where, when and whom the virus would strike.
"It was a terrifying time," recalls lawyer Alex Lam, chairman of the Sars Mutual Support Association for survivors. "Diseases like heart problems, you can blame factors like poor diet, genes, bad lifestyle.
"With Sars, you could get infected while on a flight from a happy holiday. Or on a train to work. Or taking a certain lift. You were just unlucky."
On March 12, 2003, then health director Margaret Chan alerted the World Health Organisation to the epidemic. Outbreaks had erupted in a few hot spots. On March 29, schools were shut down. Firms sent employees home. Every day, newspaper, TV and radio reports intoned the latest death toll.
Ms Erica Tse, 30, then a City University undergraduate, recalls: "No one was smiling and there was no hope in people's eyes... We didn't know how long we had to wait."
Over in hospitals and laboratories, doctors and researchers raced against time to figure out what the mystery virus was. Says Dr David Hui, head of Chinese University of Hong Kong's (CUHK) respiratory medicine division, and who handled 300 cases at the Prince of Wales Hospital: "We were fighting in the dark without knowing where the enemy was."
The uncertainty meant chaos on the front line. The Hospital Authority initially hoarded N95 face masks. Doctors and nurses were told to use just one mask per day. The same parsimony extended to disposable gowns, which were turned inside out for re-use. On April 26, the first medical worker died.
Given that Sars and the flu had similar symptoms, there were also stumbles in patient diagnosis.
Amoy Garden resident Cathy Kong, 53, coughing and feverish, saw a doctor twice and was given flu medicine. The mathematics teacher was later diagnosed with Sars.
Mr Lam had similar symptoms. An X-ray found spots on his lungs. The doctor told him: "It's almost certain you have Sars." He was treated with the Sars cocktail of steroids and ribavirin, leaving him weak and breathless.
It was only in July that his doctor confirmed he did not have Sars. Meanwhile, his boss sacked him.
In the absence of information, the government bore the brunt of public frustration over perceived ineptitude.
Dr Chan was blamed for not quarantining the residents of Amoy Garden until March 31. Medical workers worked in "a hazardous environment", said CUHK epidemiologist Wong Tze Wai. As late as mid-April, there was still no temperature screening at the border with Guangdong.
In the end, to take responsibility, the hospital chief apologised, Dr Chan was censured, and Health and Welfare Minister Yeoh Eng Kiong resigned.
Such rancour aside, the crisis saw Hong Kongers - often labelled, not least by themselves, as a materialistic breed - pull together in solidarity.
The rich donated funds while Hong Kong artists lifted morale with their songs and movies. There was also a shift in societal values.
Ms Tse, then studying for a business degree for a career in finance, became a flight attendant.
"Before, I would think about my career. I changed. What's important is to spend time with the family. You never know when something like Sars could happen again."