An investigation will be conducted by the National Bureau of Investigation (NBI) to determine the cause of the fire that hit the Department of Public Works and Highways (DPWH) Region 4B Mimaropa office, including the possibility that it was deliberately set, NBI Director Jaime Santiago said on Thursday.

Santiago said the fire originated on the third floor of the building, which houses documents related to the Mindoro flood control project. Initial findings from the Bureau of Fire Protection (BFP) indicated that the blaze may have been caused by an “octopus” electrical connection or the unsafe use of multiple extension cords and power strips.

“The fire reportedly started on the third floor due to improper and hazardous use of electrical cords and extension wires,” Santiago said, citing information from Fire Officer Captain Bernard Soriano, who leads the local fire investigation team.

But Santiago emphasized that investigators are not ruling out arson, especially given the sensitive nature of the records stored in the building.

“We do not rule out any possibility until the investigation is complete,” he said.

The NBI forensic team, in coordination with the BFP, was set to return to the site on Thursday to conduct a more thorough examination. The area has been sealed and cordoned off as a potential crime scene, with entry strictly prohibited while evidence collection and analysis are ongoing.

Santiago said that all those occupying the third floor, where the fire began, will be called to give statements, adding that investigators would also secure computers and other materials that may contain relevant information.

Reports have circulated that no flood control project documents were destroyed, but Santiago said such claims remain unverified pending a detailed probe.

Public suspicion has grown over the incident, which occurred amid an ongoing investigation into alleged irregularities in the DPWH’s flood control projects.

Santiago noted that investigators understand why people may find the timing of the incident unusual, and it is precisely for that reason that all angles will be examined.

The NBI and BFP have yet to release their final report on the cause of the fire.