At least 124 historical sites and structures in Metro Manila are vulnerable to collapse when an earthquake with a magnitude similar or higher than the Surigao earthquake happens in the country's capital.

Speaking before the International Symposium on Preserving Heritage Sites in Manila City, Secretary to the Cabinet Leoncio Evasco Jr. said there are 200 historical sites in Metro Manila. Of this number, at least 124 have historical structures that are vulnerable to collapse in case of a massive earthquake.

Evasco underlined the importance of strengthening these structures. He said heritage sites are common converging points of people particularly old churches, heritage parks, museums, and cultural sites.

Experts and advocates gathered in Manila said the heritage sites are the most vulnerable structures that will be destroyed by earthquakes given its age and number of calamities that it has withstood in the past.

Evasco, a former mayor of Maribojoc, said the 7.2 magnitude earthquake in Bohol could have killed more people if it happened early in the morning.

"Had it happened early in the morning, many of our retirees and senior citizens would have perished because they are the ones who go to church early morning," he said.

Heritage sites and experts are calling on all heritage custodians, including the government, to start making a conscious effort to save the country's heritage structures from earthquakes and other calamities facing the global community now and in the future.

Dr. Jaime Laya, chairman of Escuela Taller de Filipinas Foundation Inc., an organization of experts committed to preserving heritage sites around the world, said improvements made on heritage sites should have a sound engineering study to avoid disasters like what happened to Sto. Nino church in Cebu during the same earthquake in 2013.

"Some heritage structures dagdag ng dagdag. They keep on adding concrete without ensuring adequate foundation. Kapag nag-earthquake magco-collapse yun. Thats what happened in Sto Nino (church) in Cebu, nag-collapse kasi masyadong mabigat," Laya said.

Indonesian disaster and structural expert Lu'lu Muhammad said retrofitting must be done to heritage structures to ensure integrity of the building but this must be studied thoroughly before making any engineering move.

"We need to indicate if we need retrofitting. Heritage sites were constructed during the 1800s and before, we don't know the situation of construction at that time," he said.

Evasco said President Duterte is committed to provide funding and programs that will preserve the country's heritage structures.

"The Duterte Administration recognizes the important role our culture plays in our society. In the next six years, we will support cultural protection and development," he said.