Six people from Hong Kong and a Macau man were among 64 people killed when a Vietnamese Airlines jet crashed in flames while landing at Phnom Penh airport.
Relatives flying out from Hong Kong today include the aunt of Chanayuth Nim Anong, the 18-month-old boy who is believed to be the sole survivor of Wednesday's disaster.
His mother Sun Yan, who held a mainland passport, died in the crash.
Her sister, who refused to give her name, recalled how she saw the pair off from Kai Tak on Wednesday.
Ms Sun had been on a brief holiday in Hong Kong and was going to meet her Thai businessman husband in the Cambodian capital of Phnom Penh.
Mother and son had transferred to the ill-fated flight after arriving in Vietnam's Ho Chi Minh City, she said.
The injured mud-covered boy was miraculously pulled alive from the wreckage.