No one was seriously hurt in the two-hour blaze that started at around 2:30 a.m. inside the offices of the fourth floor.
Investigators said fire destroyed Room 401, which houses the Administrative Management Bureau-Human Resource Management of the Senate.
Pasay fire marshal Joselito Maslang said the city’s firetrucks joined the Senate’s standby firetruck in putting out the blaze.
Damage was initially placed at P120,000.
Retired Gen. Jose Balajadia, Senate sergeant-at-arms, said the fire did not disrupt regular offices at the Senate.
"We did not order anyone to go home. We just transferred those who were affected to another office," he said.
Balajadia said he has informed Senate President Pro-Tempore Juan Flavier about the fire.
Flavier is currently in-charge of the Senate since Senate President Franklin Drilon is abroad. Congress is in recess until May 15.
Although the Senate will rely on the investigation by the Pasay City Fire Department, Balajadia ruled out arson in the case.
In his initial investigation, Inspector Leo Andiso, chief of the Intelligence and Investigation Unit of the Pasay Fire Office, said the fire caused by an overloaded uninterrupted power supply (UPS) unit inside the human resource office. "Investigation showed that two computers were destroyed due to intense heat," Andiso said.
The computers were apparently left unattended by their users — a legislative staff assistant and a legislative staff officer.
Balajadia said he was unsure if the two would be slapped with administrative charges.
"Frankly I do not know, because we have not had any experience with misdemeanor charges for a fault like this," he said.
This, however, was the second fire to hit the Senate building.
The office of Sen. Loren Legarda was also damaged by fire a few years ago.
Balajadia said 10 staff members of the human resource department are now temporarily housed at the Padilla Room at the second floor to avoid disruption of services.
Elevator service and some electrical outlets were temporarily cut off yesterday, pending a thorough inspection by the Senate maintenance and electrical services.
Some electrical lines are still wet from hoses of firemen and from sprinklers, which were activated during the blaze.
"People have been constantly reminded to always unplug appliances," Balajadia said. – With Rhodina Villanueva