If Hongkongers - particularly those who had earlier fled the Cultural Revolution - were thinking about seeking a new home after the Joint Declaration returning Hong Kong to China was signed in 1984, the Tiananmen Square crackdown gave them the final push.
More than 450,000 people are estimated to have left during the massive brain drain between 1989 and 1997. And while many have returned as the feared chaos did not ensue after the handover, others have stayed away. Some have even become 'astronauts', splitting their time between families in foreign lands and businesses in Hong Kong.
Walter Sin Wai-keung, 58, is one of them. An electronics engineer and an expert in photography, Mr Sin was invited by an Australian businessman in 1987 to become a manager of a camera company.
He did not take the opportunity at the time, bowing to his wife's wish to stay in Hong Kong and take care of her mother. But, when the crackdown happened, her mother insisted they leave. Mr Sin approached the businessman again, flying to Australia just seven days after the tragic events, but the manager's job was no longer open.
'The boss was very understanding,' he said. 'He said he would help us with the immigration application because he knew we were scared of China. But the only position he could offer was as a technician.'
The engineer's wife, Janet Ng Wai-kuen, said she felt as though she owed it to her husband to move. 'I had wanted to stay with my mother. But after June 4 my mother insisted we leave. However, the position offered to my husband was no longer as a manager.'