From the investigations of the Forensics Department of the National Police Force, staffs of the Engineering Institute and staffs related to the incident, Mr. Pichaya Chantranuwat, the Director of the Engineering Institute of Thailand states that the origin of the fire is from the fire pump room on the B2 basement floor. The fire travelled from the underground floor B2 up to the 8th floor via the interconnecting duct between the B2 and 8th floor. The duct is horizontally installed and is made from fiberglass, which is not designed for high heat resistance. The heat spreading to the 8th floor’s duct caused it to collapse and obstruct the fire exit of the 8th floor which caused the smoke to be trapped and was not able to escape outside. The situation was worsened by large amount of combustibles which helped sustained and grow the fire.
Due to the old age of the building, the outdated duct design is considered to be a weak point. On the other hand, newly constructed buildings would have the heat resistant ducts installed or fire dampers inside the duct in order to prevent the air from coming inside. Building inspections for old buildings will be restricted to original structural inspections, and no emphasis will be made on the matters previously mentioned. Mr. Pichaya also states that the laws and regulations for building fires exist, but are difficult to enforce.
From our experience of surveying numerous factories, we hypothesize that the underground B2 floor, which contains the wastewater treatment equipment and other utilities, had methane gas, hydrogen sulfide gas, and ammonia gas accumulated from the wastewater treatment process. These gases can be ignited and catch fire quickly from electric sparks of the blower machine, which was inside the room, according to the news. This could be the cause of the fire incident. Afterwards, the smoke and heat rose into the ventilation duct which if no inspections were regularly performed, debris and residues could be the fire’s medium and helped spread the fire. This lead to continuous fire inside the duct due to the duct’s inability to resist fire, finally causing the pipe to be damaged, collapsing to block the exits.