With no traces of bomb, probe focuses on Serendra's centralized LPG pipeline

With authorities virtually ruling out a bomb, experts are focusing on a gas leakage as the probable cause of an explosion in a condominium that killed three people in an upscale section of Taguig last Friday.

Residents of the building in Ayala Land's Serendra condominium complex where the blast occurred still have not returned to their homes as investigators backed by scientists probe a complex pipeline for LPG fuel that probers say is the first of its kind in the Philippines.

Unlike many homes in the Philippines that use stand-alone LPG tanks, the Serendra condominium buildings have centralized systems that pipe LPG into each condo unit for cooking purposes.

"There's the potential of a gas explosion because that building has piped gas," said Dr. Carlo Arcilla, director of the UP National Institute of Geological Sciences in Diliman and one of the experts tapped by the Department of Science and Technology (DOST) to survey the blast site.

Arcilla cautioned however that probers need to gather more evidence before concluding a gas leak caused the blast.

The powerful explosion came four months after a similar incident in the area, which did not cause any injuries. Last January 30, pedestrians reported a loud noise and the smell of LPG coming from a dislodged drainage cover at the Two Parkade Building in Global City, prompting police and explosives experts to seal off the area.

Presence of gas

The occupant of Unit 501, where last Friday's blast originated, had complained that the air in the condo was making him feel like he was "suffocating" hours before the explosion.

"Kung may gas leak, posible talaga na naka-feel siya ng discomfort," Arcilla said.

Arcilla, who was also interviewed Tuesday on GMA-7's "Unang Hirit," noted that methane, propane, or butane are among those normally used in centralized gas systems, any of which could cause a powerful explosion such as the one that happened at the Two Serendra. The blast ripped off a concrete slab that fell on a passing delivery van, killing its three passengers.

The UP geologist explained that he was chosen for the investigation at Serendra because his team was equipped with a device than can detect the presence of gas in an area.

Arcilla said he was initially tapped to ensure that the blast site -- Unit 501 of Two Serendra -- would not pose dangers to probers who would be scouting the area in the next few days.

"I can surely say that the area is safe now for investigators," he added.

He said he already submitted his report on the site last Sunday, but he refused to divulge its details. His findings will be synthesized with those of other experts.

Because of the incident, Arcilla said the "joints" of the gas pipes inside the building should be checked for any leaks or "ambient gas."

He also advised the management of the property not to re-open the gas pipes while a probe is ongoing.

Probers are nearly ready to conclude that the explosion was caused by a gas leak, but they are leaving it to the Department of Interior and Local Governments to announce the results on Thursday, according to a reliable source who is part of the investigating team.

Leaked gas easily ignites

While "theoretically" gas explosions inside confined spaces are possible, Arcilla stressed several factors that need to be present: hydrocarbon vapors, oxygen, and a spark.

"Ang gas, once released in a confined space, mag-light ka lang ng bulb, puwede nang sumabog yun kung yung concentration niya ay mataas," he said.

He admitted that the K-9 dogs' failure to detect the presence of bomb components over the weekend was "very telling."

Arcilla said investigators should next look for other evidence that could point to other possible causes of the blast.

"You should piece the evidence together. What are the possibilities... In a scientific phenomenon, you should check out what is the most and least probable cause," he said.

In 2010, Arcilla was among those tapped by the government to inspect the leak in the liquid fuel pipeline of First Philippine Industrial Corp. (FPIC).

Arcilla said the fuel that leaked from the FPIC pipeline beneath the West Tower Condominium in Makati in 2010 was less threatening than gas channeled through a pipeline.

"Sa West Tower, ang pumasok ay gasoline fuel. Liquid siya. So bago pa sya mag-produce ng vapor, maaamoy mo na," he said.

"Pero kapag piped gas, hindi mo kaagad mahahalata yan kung may leak na yan. Mahirap malaman. Ang methane ay walang amoy, although hinahaluan iyan ng chemical para magka-amoy," he said.

Gas highly combustible

According to the website Gas Safe Register: "Gas is by its very nature highly combustible. Correctly fitted and maintained gas appliances ensure that gas is burned in a safe and controlled way to heat our homes and to cook with."

"If gas leaks from a faulty appliance or pipework it can spread quickly and there is a risk of it accidentally igniting, causing a fire or explosion," it added.

Gas Safe Register is the official gas registration body for the United Kingdom.

The site explained that badly fitted or poorly maintained gas appliances can produce the poisonous gas carbon monoxide which can cause headaches, dizziness, nausea, breathlessness, or loss of consciousness.

Structural integrity

Meanwhile, a spokesperson for Ayala Land Inc. (ALI) on Tuesday admitted that while most Ayala properties meet and even exceed the existing building codes of the country, he couldn’t categorically say if Two Serenda was built to specifications.

“With regards to structural integrity, we are compliant. And in most cases, we exceed the building code, with regards to integrity. However, with regards to the affected building, that is still being looked into by authorities, particularly the Department of Public Works and Highways,” Jorge Marco, Head of Corporate Communications for ALI, said in a phone interview with GMA News TV’s News to Go.

Marco also reiterated that the affected building has been evacuated, pending the investigation.

“Yung affected building, yun ang in-evacuate, sinecure ng investigating task force, hanggang ngayon ini-investigate yung insidente,” he said, noting that at this point ALI refuses to speculate on the cause of the explosion.

“I think this is something that the investigating task force will have to [answer. What caused the incident is] part of the things we are investigating,” he said.

However, Marco confirmed that Liquefied Petroleum Gas or LPG was coursed through the building.

Assistance for victims' families

Meanwhile, Marco said ALI continues to coordinate with the company of the three delivery staff of Abenson who were killed in the incident.

“‘Yung assistance na binibigay namin sa kanila, will be given through Abenson, their employer. We are coordinating with them regarding funeral and burial expenses,” he said.

“We are looking into other areas to help families. Maybe in the form of livelihood, or education for the children,” Marco added. – with Gian C. Geronimo & Patricia Denise Chiu/VVP/HS/YA, GMA News