Buildings officials will consider prosecuting the owner of an unauthorised, subdivided industrial building flat in Hong Kong that went up in flames on Saturday night, killing three. A preliminary investigation by the Buildings Department indicated that no authorisation had been given to the owner of the 10th floor unit to alter building plans and carve up the 6,000 sq ft space into 17 separate rooms, nor did it submit an application to carry out minor building works. Some of the alteration works had also failed to meet the safety standards for fire escapes and fire-resistant construction. “The [department] will issue a statutory order to the relevant persons … demanding rectification of the irregularities, collect further evidence … and consider prosecution,” a department spokesman said. This came as police and fire officials continued to investigate the tragedy at the 45-year-old Mai Sik Industrial Building in Kwai Chung, which was revealed to have lacked automatic sprinkler systems due to an exemption for such buildings built before 1973. The fire started in unit 10A shortly after 6pm Saturday. It took 30 minutes to put out the blaze. Firefighters had to knock down a locked door to get to the victims – two men, 18 to 25, and a woman, 21 – who were found unconscious in the unit’s toilet. It was understood the tenant – one of the male victims – used the space as a “hang-out” for drinking and singing karaoke with friends. He was also a part-time bartender and magic enthusiast who enjoyed mixing drinks and experimenting with flammable phosphorus powders in the flat. Officials were investigating leads and the victims’ backgrounds to find out the cause of the blaze. Liquor and bartending equipment, televisions, microphones and soundproofing foam were discovered inside the unit. Hong Kong security minister warns of ‘hidden’ fire threats in city’s old buildings Building tenants told reporters on Sunday that the building’s flats were used for multiple purposes, ranging from offices, workshops and storage to band rooms, church services and even residences. Kwai Tsing district councillor Wong Yun-tat said the government needed to strengthen legislation on industrial building safety as only those subject to revitalisation projects in the neighbourhood were equipped with fire hoses and sprinkler systems. A lack of policy support for small businesses and those involved in the arts or creative sectors was also forcing many to utilise space in old, low-rent industrial buildings, he added. Security minister John Lee Ka-chiu on Sunday said police, buildings and fire services department officials were investigating whether the fire was a result of breaches in safety or fire regulations. He said the Security Bureau would be tabling draft legislation on raising fire safety standards for old industrial buildings in the upcoming legislative year. It would cover fire escapes, ventilation systems as well as automatic sprinklers.