By LYN V. RAMO
www.nordis.net

MANKAYAN, Benguet — Odellon Wallang and two of his children were inside their house along Aurora Street around 11:45 in the morning of June 5 when they were frightened by a loud crashing sound he likened to a plane crash.

He rushed to the window to see the whole mountainside going down. “Napaipusak a mapmapanen ti bantay,” (I caught the tail of the mountain sliding down) he told Nordis.

Immediately, he rushed to warn his neighbors, only to see them packing up, some already fleeing the area. He then returned to pick up his kids, as he caught a glimpse of the trail to the main road had already gone.

“I kicked the fence off and not long after we left, our house went down.”

Odellon was still shaking, his voice quivered as he retold his close encounter with disaster. Five other houses also collapsed.

These belonged the families of Pedro Casaldo, Ben Asiong, Abdon Costian, Salvador Pacsayan and Mrs. Gloria Ticuala; who returned after they were displace by the 1999 sinking in the same area. The last three are gradeschool teachers here.

There has been major ground subsidence in the area the past years. The last in 1999 when some 55 houses were pulled down along with the landslide. It has lately been raining for two days before the area practically caved in.

Warning signs
A teacher from the Lepanto National High School said a riprapped wall was bulging, indicating a weakening in the wall and inevitable collapse.

“Napunno ti luyot,” (It was full of mud) she said.

Mankayan National High School Principal Pablo Khayog Jr. noticed a tree inside the campus changed position. He said he even called the attention of town officials in a letter he sent in March, this year.

“They did not bother to investigate. They could have done some mitigating measures,” Khayog told Nordis in an interview Wednesday.

The ground subsidence occurred in the former site of the Mankayan Central School (MCS) to the Mankayan National School (MNHS) athletic oval. MCS is now inside the MNHS campus since it was displaced by a similar disaster in 1999.

Previous incidents
The National Institute of Geological Sciences (NIGS) of the University of the Philippines, in an investigation report it made on the Colalo lanslide in July,1999 cited major subsidence threats in the Poblacion, Colalo and Sapid areas.

The NIGS report said, “The subsidence in Mankayan was initially reported by residents in 1972,” quoting an LCMC report in 1984.

MCS was one of the two subsidence sites cited in the NIGS report in 1976. The other is some 300 meters to its southwest along Magambang Creek. MNHS and a large part of Aurora Street were also reported to be sinking.

That year, NIGS observed some cracks running some 80 meters along Aurora Street. It also reported tilted railings, vertically translated trees; cracked foundations and the sagging rooftops of several houses, as among the conspicuous pieces of evidence of the subsidence along said road.

Not blaming the mines
In the absence of an independent investigation, town officials chose to refrain from stating that large-scale mining activities are responsible for the collapse of Aurora.

Residents however, insist that the abandoned and sealed underground tunnels may have already collapsed and may have triggered the disastrous ground movement.

NIGS, in its recommendations, mentioned the investigation of the competence of the alleged underground tunnels, which were last investigated in 1974. It also proposed a detailed structural and geologic mapping of the subsidence area, as well as monitoring of the rate of subsidence.

Relocation of residents and business establishments were also then recommended, underscoring consciousness-raising activities about the real threat to life and property.

MGB points to fault lines traversing the area of subsidence as evidenced by the nature of landslide materials composed almost wholly of soil and crushed rocks. It explains the continuous soil creep and slope movement, the June 11 MGB report stated.

In the meantime, while government officials and private groups prepare to take steps to mitigate the effects of large-scale ground subsidence, landslides and erosion in the area, the Lepanto Consolidated Mining Company continues its large-scale mining operations for gold.# nordis.net