The 1968 Casiguran earthquake occurred on with a

moment magnitude The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...

of 7.6 and a maximum

Mercalli intensity The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

of IX (''Violent''). The thrust earthquake's epicenter was in Casiguran,

Quezon Quezon, officially the Province of Quezon ( tl, Lalawigan ng Quezon), is a Provinces of the Philippines, province in the Philippines located in the Calabarzon Regions of the Philippines, region on Luzon. Kalilayan was the first known name of th ...

(now part of

Aurora An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of bri ...

province). A small non-destructive tsunami was generated and at least 207 people were killed. The majority of the deaths occurred in the collapse of a six-story building in Manila.

Damage

Manila Manila ( , ; fil, Maynila, ), officially the City of Manila ( fil, Lungsod ng Maynila, ), is the capital of the Philippines, and its second-most populous city. It is highly urbanized and, as of 2019, was the world's most densely populate ...

, many structures that suffered severe damage had been built near the mouth of the

Pasig River The Pasig River ( fil, Ilog Pasig) is a water body in the Philippines that connects Laguna de Bay to Manila Bay. Stretching for , it bisects the Philippine capital of Manila and Metro Manila, its surrounding urban area into northern and souther ...

on huge

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

deposits. A number of buildings were damaged beyond repair while others only suffered cosmetic damage. 268 people were reported to have died during the collapse of the six-story