20,000 people displaced by the Philippine earthquake that killed at least 37

Rescuers searched ruined buildings in the southern Philippines on Tuesday to ensure no one was still trapped a day after one of the strongest earthquakes to hit the country in a half-century killed at least 37 people and displaced more than 20,000, The Associated Press reported.

Only four people were considered missing on official records in the southern provinces near where the 7.8 magnitude quake struck Monday morning, but the Office of Civil Defense acknowledged several collapsed and heavily damaged buildings must be thoroughly inspected for possible survivors or casualties.

The earthquake centered off Mindanao, the second most populous Philippine island, injured nearly 500 people and displaced more than 20,000, most of whom fled to emergency shelters.

Many people who left their homes feared a tsunami. Waves up to 1.4-meter (4.6-foot) above tide level were measured in the Philippines, but the only tsunami damage reported was to six shanties on stilts in a coastal village. Smaller waves washed ashore in Indonesia and Palau and as far away as southern Japan.

Monday’s earthquake was centered at sea at a depth of 33 kilometers (20 miles), about 32 kilometers (20 miles) southwest of Maasim town in Sarangani province.

It was set off by movement in the Cotabato Trench and was the strongest since the same undersea depression triggered an 8.1-magnitude quake that whipped up tsunami waves on Aug. 17, 1976, said Teresito Bacolcol, the director of the Philippine Institute of Volcanology and Seismology.