A 10-year-old boy was killed after his grandmother tried and failed to wake him as fire raged through their rooftop home in Shamshuipo yesterday. The blaze started shortly before 2am in the hut on top of a six-storey block in Tai Nan Street while the boy's father, Tang Yiu-fai, was out celebrating his 44th birthday. Mr Tang collapsed on returning to find his son, Wing-tai, was dead. The home is one of a series of illegal rooftop structures in 100 buildings in the area, which are due to be demolished by the Government. When the blaze started, Wing-tai, a Primary Five student, his grandmother and an 80-year-old woman flatmate were at home. 'When I woke up to go to the toilet, I discovered the fire in the living room and a rice cooker and furniture alight,' the grandmother told the boy's father. She said she could not wake Wing-tai and fled for help. The flatmate, who suffers eye problems, had already gone. A woman from the sixth floor said she was awakened when dense smoke spread into her flat and she heard shouts of 'fire'. As firemen arrived, a second boy was found trapped alone in another rooftop home shouting for help. He was rescued unhurt. Firefighters used two jets and breathing apparatus teams to put out the blaze by 2.14am. The charred body of Wing-tai was found in the lower deck of a bunkbed. The 80-year-old flatmate suffered 10 per cent burns to her head and hands, while another 69-year-old male resident was overcome by smoke. They were taken to Kwong Wah Hospital where the woman was in a critical condition and the man in stable condition. The father, a part-time drainage worker, was sent to hospital and discharged later. He blamed himself for his son's death, saying the boy might have been saved if he had not gone out. Mr Tang, a divorcee, his mother and Wing-tai moved into the unit about three years ago, paying around $1,700 to rent one of the two bedrooms. His eldest son, Wai-tai, lives with his father-in-law. Mr Tang went to the Social Welfare Department yesterday to seek help. He told officials he had lost his son, his home and had no money. It is the second time an illegal structure has caught fire and killed a resident within eight days. Last Monday, Wong Lin-chor, 80, died when a ground-floor illegal structure used as a fruit stall caught fire in Prospect Building, Yau Ma Tei.