Two hikers whose bodies were found in a stream yesterday were probably washed away by a flash flood in Pat Sin Leng Country Park on Sunday, police said.
They believe Wong Chi-kin, 24, a secondary school teaching assistant, and his friend Hung Wai-man, 25, a social worker, were taking a rest by the Ping Nam stream at about 2pm on Sunday when the deluge struck.
Their bodies were found at the bottom of an eight-metre pool.
The park is in the northwestern New Territories.
A hiker was washed away by a flash flood in the same stream last July, and found dead in the same pool.
Wong's brother asked police to look for him at around 4am yesterday after he failed to return to his Sha Tin flat.
Hung's mother called police at 10am after failing to reach her son.
An air and land search involving nearly 100 fire and police officers began before noon. Wong's red rucksack was spotted at the stream at 12.45pm by a Government Flying Service helicopter.
Divers found the men's bodies at about 2.30pm, 100 metres from their rucksacks. A camera found in a rucksack showed that the men took photos of the area at 2pm on Sunday. That is the same time a sudden downpour struck Sha Tau Kok.
'We believe the two victims were hit by a heavy deluge and washed away from where they had stopped by the stream,' a police spokesman said.
One of the victims had serious head injuries.
'One of them may have hit his head on a boulder while being washed away, and the other one possibly tried to save him but was drowned,' the spokesman said.
Postmortem examinations will be carried out today.
Other hikers at the stream reported seeing a flash flood.
Li Kim-fung, of the Hong Kong Stream Explorers Hiking Club, was higher up the stream with a group of 30 hikers at the time. 'There was a flash flood after the downpour,' he said. 'The heavy deluge lasted for about half an hour. We had to leave the stream.'
He said people hiking in or near a stream should stay alert to the chance of flash flooding after heavy rain.
Wong, a graduate of Polytechnic University, joined Tsang Pik Shan Secondary School in Ma On Shan as a teaching assistant last September.
He taught computer studies to pupils at junior levels and organised extracurricular activities.
School principal Lau Chun-hung said he was saddened and shocked by Wong's death.
'Chi-kin was a responsible and hardworking teaching staff and a good colleague,' he said. Lau said social workers would offer counselling to pupils today.
The Agriculture, Fisheries and Conservation Department warns people to pay attention to terrain and weather conditions while hiking.
'Avoid steep inclines and deep pools of water in order to prevent falls or drowning' says one of its tips.