A fire station officer and a worker at the scene of a class-three blaze that engulfed a Tsuen Wan electroplating plant and killed a fireman in 2007 saw no sprinkler systems operating during the fire.
Emergency sprinklers at the building were meant to turn on once temperatures rose above 68 degrees Celsius, but failed to work on the night of the fatal fire - May 21, 2007 - said Tsuen Wan Fire Station senior station officer Lam Lung-kwan, who led the team of firemen that fought the blaze.
Even after Mr Lam had confirmed with a fireman in charge of a water tanker on the scene that all the building's emergency water systems had been switched on, he noticed no sprinklers were operating, he said.
One worker, Chau Wing-sing, said: 'When I left the building, I was not wet.' Mr Lam and Mr Chan were speaking at the inquest for fireman Wong Ka-hei, who died in the blaze on the 6th floor of the 23-storey QPL Industrial Building. The inquest began yesterday, is expected to last six days and call 56 witnesses.
Other workers from the industrial building, employees of Vast Tech Limited, have backed up Mr Lam's story, saying no sprinklers came on when the fire broke out. Some said they did not hear any fire alarm until they had left the floor where the plant was situated, and could not recall seeing maintenance work being done on the building's fire safety systems before the incident.
Mr Lam said he saw signs of a phenomenon called a flashover, when flames started to replace the smoke that hovered near the ceiling above the fire. The flames moved towards the firemen and crept over their heads, he said. A flashover occurs when all objects in a room burn and emit smoke and gas, radiating heat that spreads to surrounding objects, Mr Lam said. When the temperature rises above 600 degrees the gases ignite, resulting in a rapid and widespread flame that engulfs the space in seconds.
He said he pointed his fire hose at the ceiling to stall the flashover, but the fire kept burning: 'I realised that we couldn't put out the fire, so I told all my colleagues to leave.'
Later he learned that the ceiling was covered in glass wool [a fire-resistant, thermal insulation material] and that the blaze burned part of it.
Wong was a healthy man who exercised regularly and did not have heart problems or breathing difficulties, his father, Wong Tak-shing, said.
The fire started close to midnight, the workers said. One placed its origin at a silver-plating reservoir in the middle of the fourth electroplating production line.
The inquest continues today before Coroner William Ng Sing-wai.