MANILA, Philippines - Filipinos poured out of buildings and shopping malls in a massive drill across Manila on Thursday to brace for a 7.2-magnitude earthquake that experts fear could kill tens of thousands and displace millions.

The Philippines is one of the world's most disaster-prone countries in the so-called Pacific "Ring of Fire," where earthquakes and volcanic activities are common. A 7.7-magnitude quake in 1990 killed nearly 2,000 people on the main northern island of Luzon, which includes Manila.

A fault line cutting across the sprawling capital of more than 12 million people and nearby provinces could shift anytime, based on its seismic history, said Renato Solidum, head of the Philippine Institute of Volcanology and Seismology.

"We don't have a culture of preparedness," said Metropolitan Manila Gov. Francis Tolentino, adding work needed to be done to reduce a potential death toll estimate of 35,000.

When alarms sounded, tens of thousands rushed out of buildings and shopping malls in Manila.

The government is planning to reinforce at least five bridges, including a key span that connects the main EDSA highway in the capital, to shield them from critical damages in a major earthquake, said Secretary Rogelio Singson of the Department of Public Works and Highways.

Several old buildings in the capital that do not comply with the safety code also needed to be reinforced, he said.

Such drills are crucial because they familiarize people with simple things, like the location of fire exits, and prompt them to prepare flashlights and whistles that could save lives in real disasters, said Mark Bidder of the U.N. Office for the Coordination of Humanitarian Affairs.

He cited Japan's resiliency against natural disasters, including major earthquakes, because of its effort to expose residents to drills starting at a young age. "They're not afraid of earthquakes because they know what to do," Bidder said.