A middle-aged woman died after she was blown out of her 15th-floor flat on to the street below when a gas explosion rocked the public housing estate where she lived in Kwai Chung yesterday. It is suspected the woman, surnamed Lam, 44, committed suicide. She had lived alone in her top floor apartment. Neighbours said there were two to three blasts. One horrified resident, surnamed Ma, said he saw Lam fly through the air and land on the terrace below. 'The explosion was loud and seconds later I saw a person falling,' he said. Mr Ma added that Lam appeared to be standing on a 15th floor window's edge before the second explosion. Poon Ming-wai, deputy commander of the New Territories South fire services, said firefighters were hampered from entering the flat as the front door had been blocked by a table and chairs. He said three liquified petroleum gas (LPG) cylinders were found near the woman's bed and one of the cylinders was leaking. The case has been forwarded to police for investigation. Glass and debris were sent showering down from Lam's flat when the explosion happened at 1.20pm. Her half-naked and badly burned body was later found on the terrace. The blast, which hit the 15-storey building in Ying Keung House on Lai King Estate, Kwai Chung, was triggered by the leaking LPG cylinder, firemen said. The fire was eventually put out at 2.10pm. Some 120 residents in the building had to be evacuated. Another neighbour, who also lives on the 15th floor, said he heard a loud bang and glass breaking. 'I then went next door and saw the wall had been bent by the blast,' he said. The reason for Lam's suspected suicide was not immediately known, and police said no note had been left in the flat. A man sustained a minor cut to his hand as he tried to sound the fire alarm by breaking the glass casing. A shopkeeper told police that Lam had ordered two LPG cylinders three days ago. Under fire regulations, storing more than 130 litres of LPG - equivalent to four cylinders - in an apartment is an offence. Yesterday's blast was the second in about a month. Three women died and 21 other people, mostly firefighters, were injured when a fireball tore through a 15th-floor flat in Tsui Chuk Garden, Wong Tai Sin, on October 30. The blast was triggered as firemen broke down the door to the gas-filled flat in response to an apparent suicide call. The charred body of 78-year-old Siu Yee-yau was found in the flat. Her husband, Chan Kuk-sun, 80, was arrested and charged with her murder. Two female neighbours on the same floor, Ngan Hau-lan, 75, and Sze Chui-ngor, 46, also died.