A government investigator into a blaze that led to the deaths of 37 staff at the southern Philippines 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 broke out at a furniture and fabric store on the third level of a mall, the New City Commercial Center (NCCC), and then engulfed the offices of the U.S. 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 didn't work at the firm was a mall security officer. More than 100 SSI employees who were on duty that day managed to escape, of whom six were injured.