Two doors, suspected to have been installed illegally, were to blame for the rapid spread of flames and smoke into two blocks of flats in Mong Kok during Hong Kong's deadliest fire in 15 years, an investigation has indicated.
The two doors, on the mezzanine floor of the two eight-storey buildings at 192 and 194 Fa Yuen Street, were linked to a joint staircase where nine people were found dead after the fire on November 30 last year.
'We are now checking with the Buildings Department to see whether the two doors are illegal alterations,' a source said, adding that neither door was on the original plans.
According to the Fire Services Department investigation report, the doors, which quickly burned away, were among the main causes of the fire's rapid spread into the buildings and the staircase, which filled with choking fumes.
Results of port-mortem examinations showed the victims died from suffocation, according to the source.
The fire, which started in a hawker stall selling children's clothes, also injured 34 people.
A faulty electric cable in the stall near the staircase exit is believed to have been the source of the fire.
'We suspect the plastic protective coating of the cable was damaged, causing sparks that ignited goods in the booth,' said a police investigator. 'We are waiting for a final comment from an independent expert [Professor Ho Siu-lau of the Polytechnic University] to see whether this is established.'
The officer said the investigation also showed an electric switchboard was suspected to have been illegally moved into a booth from outside.
The hawker stall in the popular street market burst into flames in the early hours of November 30. Wind spread the flames to other booths before they spread to the mezzanine-floor rooms of the two buildings through canvas awnings, according to police.
The report from the Fire Services Department said the design of the buildings was another factor that led to the intense heat and dense smoke spreading into the two blocks.
It said the heat and smoke accumulated in a space under the first-floor concrete canopy and that the fire burned into two mezzanine-floor rooms when the windows broke in the heat.
More than 300 firemen took eight hours to put out the blaze, which raised concern over the dangers of subdivided flats and the safety of hawker stalls.
'The investigation report has been forwarded to police for onward submission to the coroner,' said a spokesman, refusing to give details.
It is understood that details of the fire-fighting, rescue operation and fire prevention measures are contained in the report.
However, the report did not touch on the cause of the fire, saying this would be left to police. It also did not say whether the blaze was suspicious.
Initially, the fire was suspected by the Fire Services Department to have been caused by arson, as no natural cause was established and a fire investigation dog sniffed out fire accelerant at the scene.
'Laboratory tests by chemists found no fire accelerant at the scene,' a police officer said. 'Up to now, there is no evidence of arson.'
He said police were analysing the reports and recommendations from the Fire Services Department, Buildings Department, and Food and Environmental Hygiene Department. Kowloon West regional crime unit is compiling a full report which is expected to be ready in one or two months and will be submitted to the Coroner's Court.
Police deployed more than 300 officers to investigate the fire and interview more than 300 people in the first week. Hundreds of items were taken for laboratory tests. Following the blaze, the Buildings Department targeted 339 similar buildings looking for fire hazards and illegal building work. Government checks on hawker stalls were also stepped up.