A HIKER went missing after being washed away in Castle Peak during yesterday's downpour, which caused flooding and traffic disruptions across the territory. Weathermen forecast continuing thunderstorms this morning, easing to occasional rain. At about 3.45 pm yesterday - when the rain was at its heaviest - Mr Lam Kwong-hung, 33, was caught by a sudden gush of water at Pak Shek Hang. More than 10 friends, including his girlfriend, watched helplessly as he was washed away. They walked for two hours along the trail from Yuen Long to Tai Lam Chung to call the police. Two divers searched nearby streams and catchment areas but were recalled at about 8 pm without finding any trace of Mr Lam. Firemen believe he could have been washed along catchment drains and into the Tai Lam Chung reservoir. The Royal Observatory said the torrential rain was caused by a trough of low pressure moving south from China. An average of 52.7 millimetres of rain was recorded up to 10 pm, with Tsuen Wan recording more than 80 millimetres. About 40 reports of flooding came in from all over Hongkong, but the hardest hit areas were Yuen Long and Tsuen Wan. Ten incoming planes were diverted to other airports while one arriving and six departing flights were delayed. Mr Alan Cooksey, a top British rail expert coming in to investigate the recent Mass Transit Railway train separation, was stranded in Taipei last night after his flight was diverted. Traffic accidents were widespread, with at least three Kowloon Motor Bus routes being diverted around crashes. The strong wind and tides caused an oil tanker to ram a foundation of the Tsing Yi North Bridge. The 497-tonne Singaporean tanker Merlion almost ran aground. A 76-year-old woman suffered slight head injuries when a 30-metre-tall tree collapsed on to the roof of her house in Ching Man Village, So Kon Po, at 6 pm. The First Division soccer match between Kui Tan and British Forces was postponed and the last two races from yesterday's 10-race card at Macau were cancelled.