Manila: Authorities on Sunday urged Filipinos to be prepared after successive earthquakes struck the Southern Tagalog region recently.

“We never know when an earthquake will occur. But we should know what to do before, during and after the occurrence of such events. Regular safety drills should be done to familiarise citizens with safety and disaster preparedness measures,” said Senator Loren Legarda.

At least two successive earthquakes with magnitudes of 5.6 and 6.0 jolted the Southern Tagalog Region on April 4 and 8, with the terrain and structures in the province of Batangas suffering damages. The tremors were felt in nearby areas including Metro Manila.

Legarda reminded disaster management agencies, local government units (LGUs), community leaders, and citizens to be on guard for the so-called “Big One”, an earthquake projected by geologist to be of at least, 7.2 magnitude that could hit Metro Manila.

“The key to effective disaster prevention is planning. It is important to know if our location is near an active fault and prone to liquefaction or landslide, which may cause damage to houses or buildings. “We have to ensure that buildings are not standing on active faults. Evaluation and retrofitting of public and private infrastructure is crucial in ensuring that buildings, bridges and other similar structures can withstand strong quakes,” she said.

The Senator said earthquakes turn into major disasters due to unsafe structures — poorly built constructs, buildings in inappropriate places, inadequate design and materials specification, and due to shortcuts used in construction.

The earthquake jolted Mabini, Batangas and other nearby areas, affecting houses and major infrastructure, including energy facilities, causing power outage in some parts of the province.

According to the Philippine Institute of Volcanology and Seismology, Intensity 7 was recorded in Mabini, Batangas while varying intensities were monitored in other areas of the province as well as in, Cavite, Oriental Mindoro, Bulacan, Metro Manila, Quezon, Pampanga and Camarines Norte in the Bicol Region.

In some parts of Batangas, particularly the island municipalities, residents evacuated to safer areas a precaution following the twin earthquakes.