THE seven-year-old daughter of the two hikers who were swept over a cliff in a landslide on Hong Kong's highest peak on Sunday watched helplessly as her parents fell to their deaths. The full scale of the tragic deaths of Leung Ka-lok, 33, and his wife, Leung Ng How-kuen, 31, on a slope near Ng Tung Tsai on Tai Mo Shan emerged yesterday, sparking a police investigation to put hikers minds at ease over the safety of mountain trails. The mother of the dead man, Leung Lo Hing, 63, yesterday recalled watching her son and daughter-in-law slip on a muddy slope as they struggled home in fading light. ''My daughter suggested we all should stay where we were and wait for help but my daughter-in-law [Leung Ng How-kuen] said she could not wait. ''As she walked down the path, she suddenly stepped on some loose soil and slipped. My son tried to rescue her but he also plunged down. ''I didn't know what to do. We were all in a state of shock.'' Also travelling in the group were the senior Mrs Leung's daughter, her boyfriend and the dead couple's seven-year-old daughter, Ho-kay. ''I don't know what to do with the little girl . . . we are having to lie about her parents' deaths,'' said Mrs Leung. ''It is a problem for me to look after her, particularly with her homework because I am illiterate. Also, the girl suffers from diabetes.'' The Assistant Divisional Commander (Administration) in Tai Po, Chief Inspector Stephen Brown, said an inquest into the deaths of the couple, who fell 45 metres, was likely. An autopsy will be carried out on the couple, who are believed to have died from multiple fractures. Two students who met the stranded family on the hill and tried to rescue the pair were injured. Kwok Chun-chiu, 17, was semi-conscious after he fell about 30 metres down the slope. His friend, 20-year-old Chong Kan-chou, managed to climb back up and trek for 90 minutes to alert police. Mr Chong was treated at Prince of Wales Hospital and discharged at about 6 am yesterday, while Chun-chiu was still in satisfactory condition last night. An uncle of Chun-chiu said: ''My nephew fractured his lower spine and pelvis and bruised his arm. His friend, who was slightly injured, climbed back up the slope and walked for 90 minutes to use a telephone to raise the alarm. ''He [Mr Chong] had lost his shoes and had to be given another pair by the owner of a store after he made the phone call. He then took the rescuers to the scene.'' A Civil Aid Services' senior training officer, Edward Au Yin-shan, said the rescue was made more difficult by the remoteness of the site and the fact that it was dark, which stopped helicopters being used. Rescuers struggled down the slope on ropes and it was not until 6.10 am yesterday that the last injured hiker was put into an ambulance. Veteran mountaineer Chung Kin-man said the tragedy might have been avoided had the family prepared themselves better for the walk. ''Ng Tung Tsai itself is not dangerous but they should have made preparation before setting off, including talking to people who had hiked the trail and checking the weather,'' he said.