A high-level investigation has been launched to probe the death of a young firefighter who, along with six of his colleagues, were engulfed by fire during a third-alarm blaze at

a Tsuen Wan electroplating workshop early Tuesday.

One of the six injured, senior fire officer Chin Kwok-ming, 45, is in critical condition at Yan Chai Hospital while another fireman, Lee Kwok-ming, 36, is in stable condition at Princess Margaret Hospital. The other four went home after treatment for burns.

The dead man, fireman Wong Ka- hei, 27, who had eight years' experience, was the last officer to exit the workshop on the sixth floor of an industrial building at 126-140 Texaco Road, Tsuen Wan.

Wong and his team were apparently hit by a flashover, one of firefighters' most feared phenomena, according to Director for Fire Services Joe Kwok Ching-keung.

A flashover is understood to be the near simultaneous ignition of all combustible material in an enclosed area.

Flashovers occur when most surfaces in a space are heated to the point at which they give off flammable gases that are hot enough to sustain combustion.

"We will set up a special committee to study why there were so many casualties," Kwok said.

"But when it comes to fire rescue work, a flashover or a backdraft are the fireman's biggest enemies." He said it appeared the water sprinkler system did not work.

Kwok said Wong was the last one to be evacuated from the scene and was unconscious when brought out by his colleagues.

He was rushed to Yan Chai Hospital but was certified dead at 1.33am.

Former director of fire services Lam Chun-man said flashovers happen suddenly and cannot be predicted.

In addition, a fireman's coat can only withstand heat of up to 200 degrees Celsius whereas a flashover could get as hot as 500 degrees.

Four factory workers, including two who escaped the blaze by hanging on waterpipes outside the building, were rescued before the flashover.

The fire broke out late Monday evening and was soon upgraded to third alarm.

Twenty-six fire engines and nine ambulances were deployed to the area, which covers 200 square meters.

Four breathing apparatus teams and six water jets were used and the fire was brought under control at 4.16am.

New Territories South divisional commander Szeto Yat-san denied suggestions the division had underestimated the fire.

"Our gear was up to international standards and according to our working guidelines, all firemen are told to be alert when dealing with fires in electroplating factories where chemicals are stored," Szeto said.

Chief Executive Donald Tsang Yam-kuen, Secretary for the Civil Service Denise Yue Chung-yee and Secretary for Security Ambrose Lee Siu- kwong all expressed their deep condolences to Wong's family.

In his blog, Tsang lamented the recent loss of a nurse and Wong while carrying out their duties.

"Their passing away has saddened and touched me ... on behalf of Hong Kong citizens, I salute you," Tsang wrote.

"[Hong Kong's disciplined services and medical staff] will never shy away from danger. They are serving the public silently. Every one of them is an anonymous hero."

Later, in an interview with The Standard, Tsang said he was very sad over the death of a fireman. He also said the other fireman, Lee, who was in stable condition, could be released as early as today. He said Lee's injury was caused by the heavy gear he carried.

Tsang, who had visited Lee in hospital, said he could not understand why firemen had to carry such heavy gear.

He said he had been informed the fireman in critical condition had suffered burns to the throat as a result of inhaling the hot air accompanying the flashover.

He said Hong Kong's fire services had demonstrated courage, team spirit and professionalism and he was pleased the families of the injured support each other through such tough times.

Civil service chief Yue offered her condolences to Wong's family and wished the injured firemen a speedy recovery.

"The Civil Service Bureau has been in contact with the Fire Services Department and will make every effort to help the families of the deceased and the injured during this sad and difficult period," she said. Lee said the government will give all necessary support and assistance to Wong's family.

Hong Kong Fire Services Department Staffs General Association chairman Chui Chi-keung said he hoped the critically injured fireman would pull through.

"He can't talk because he's full of tubes. But he is looking okay. We are just glad to see he is in a good mental state," Chui said.

Wong, who joined the Fire Services Department in July 1999, was unmarried and lived with his parents and two sisters