DAVAO CITY (Philippines) • A government investigator probing a blaze that led to the deaths of 37 staff at the southern Philippine offices of an American market research firm says there are indications of fire safety lapses that may have contributed to the tragedy.

The Dec 23 blaze in Davao City broke out at a furniture and fabric store on the third level of a mall, the New City Commercial Centre, and then engulfed the offices of US firm Research Now SSI, on the fourth floor of the same building, in choking smoke.

The only person among the 38 killed in the fire who did not work at the firm was a mall security officer. More than 100 SSI employees at work day managed to escape, of whom six were injured.

Initial evidence from an ongoing investigation by Philippine government agencies indicates sprinkler systems on the third and fourth floors of the building were not working as their valves were closed, said Senior Superintendent Jerry Candido, who is director of logistics at the Philippines' Bureau of Fire Protection and one of the lead investigators into the fire.

Mr Candido said SSI employees may have been unaware of the fire beneath them for some time because their office had its own alarm but it was not connected to the mall's system.

His comments are the most extensive yet made publicly on the progress of the investigation.

Mr Candido cautioned that the investigation is still some way from being completed and it has yet to reach firm conclusions, particularly on the issue of liability.

He added that it was the responsibility of both building owners and tenants to make sure that alarm and sprinkler systems were installed and operating. Under the nation's fire code, if there are two alarm systems they should have been integrated.

Investigators are also looking at whether the ceiling material in the call centre was flammable, but have not drawn any conclusions.

Mr Candido also said the investigation is looking at some major structural questions concerning the SSI offices and how they related to the rest of the mall - issues that may not have put anyone in breach of regulations.

While SSI's fire exits would have passed inspection, only one of them had stairs leading directly outside the building. The others headed back into the mall and these areas quickly filled up with smoke, making them useless as a means of escape, Mr Candido said.

He separately told reporters that initial findings indicate the fire was caused by an electrical problem in the ceiling at the furniture and fabric store, and was exacerbated by the failure of the sprinkler system on that same floor.

Davao City fire marshal Honee Fritz Alagano said soundproofing in SSI's offices meant that staff may not have heard the alarm go off in the mall. She also said it is clear that some employees went to their lockers to get their mobile phones before trying to evacuate, wasting precious time.

SSI, which had about 500 employees at the Davao operation, is part of the Philippines' US$23 billion (S$30 billion) business process outsourcing (BPO) industry.

President Rodrigo Duterte, who was Davao's mayor for 22 years and was credited with boosting its economy by luring BPO firms, has promised relatives of victims that the truth will come out.

REUTERS