A stunned silence settled over Pak Sha Village last night, broken only by the sound of firecrackers to dispel evil spirits. Hundreds of parents came out into the street, vowing they would never allow their children to walk alone outside again. 'What kind of beast is capable of doing such things? The man must be completely out of his mind,' said a woman who lives on the same floor as Yim Pui-shan, the girl who was found dead on Friday. 'Pui-shan was my daughter's good friend. She was so lovely. I never thought anyone would harm her. 'My daughter felt really bad when Pui-shan went missing. When we saw the news on TV last night, she cried a river. My whole family is now trying to calm her down.' Hui Suk-wai, the principal of Wing Yan Primary School, where Pui-shan studied, said she was a 'student of excellence' who was good at her studies. 'Pui-shan had made a lot of good friends in school. She was helpful and got along very well with her friends from different grades. It is very sad to lose Pui-shan,' Ms Hui said. She said eight pupils who were close friends of Pui-shan had taken the news particularly hard. 'The students were upset and cried. I hope they can overcome the trauma after they return from the Christmas holiday,' the principal said. Psychologists from the Education Department and school social workers yesterday provided counselling for students and teachers at the school. Ms Hui said the school made an announcement about the tragedy to all students and held a one-minute's silence during the morning assembly yesterday. 'We also call on parents not to let their children alone in the streets to avoid a repeat of the tragedy,' she said. Y. L. P. M. S. Alumni Association Primary School headmaster Keung Wai-wing rushed to Pak Sha Village when he heard another body, believed to be that of Chan Lok-man, had been found in a sealed drain. He described her as one of his best pupils. 'I have met Lok-man's family. It's a great loss for us. We expressed our deepest condolences to them. On Monday I will speak to the rest of the school. I hope they can recover from this brutal tragedy,' said Mr Keung. University of Hong Kong criminologist Rod Broadhurst said last night such a tragedy was extremely rare in Hong Kong. Declining to comment directly on the case, Mr Broadhurst said the suspect's actions might have been triggered by his wife leaving him. He said that, in general in such cases, there might be a pattern of pathological behaviour before a violent act.