A powerful 7.8‑magnitude earthquake struck offshore southern Philippines on Monday morning, centered about 13 km southwest of General Santos. The tremor caused building damage, power outages and prompted tsunami warnings for parts of the Philippines, Indonesia, Malaysia and beyond.

General Santos feels the strongest quake of 2024

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) said the quake hit at 7:37 a.m. local time at a depth of roughly 10 km, making it the most intense seismic event in the country this year . Director Teresito Bacolcol told the Associated Press that videos showed damaged structures and debris falling from buildings , including a partial collapse of a small commercial office in the city.

General Santos, a tuna‑processing hub of more than 700,000 residents, reported power cuts and tricycle taxis struck by falling debris. DZRH radio in Manila confirmed that staff at the station’s provincial branch escaped unharmed, but it was unclear whether other occupants were trapped in the four‑story office building.

Pacific Tsunami Warning Center predicts up to 3‑metre waves

The Pacific Tsunami Warning Center (PTWC) issued alerts for the Philippines, Indonesia and Malaysia, warning that coastal waves could reach three metres in some Philippine provinces. PHIVOLCS monitored one‑metre waves in Sultan Kudarat and Sarangani, while smaller surges were noted in neighboring regions.

Indonesia’s Meteorological Agency recorded an 83‑centimetre surge off Sulawesi, and Malaysia’s Sabah state also received a warning. The PTWC extended advisories to Taiwan, Japan, Papua New Guinea and several western Pacific islands, though Guam’s alert was lifted after two hours and Hawaii faced no threat.

Aftershocks continue, USGS reports magnitude‑6.5 tremors

Following the main shock, the U.S. Geological Survey logged aftershocks as strong as magnitude 6.5, underscoring the ongoing instability of the Cotabato Trench—a deep‑sea fault line that triggered the initial event. Different agencies reported slight variations in depth, with the USGS measuring the quake at 55 km deep.

President Ferdinand Marcos Jr. urged residents in vulnerable coastal zones to move to higher ground immediately, emphasizing that “your life is more important than anything left behind.” Disaster‑response teams were placed on standby, and the national government pledged that Mindanao would not be left behind.

Why the Cotabato Trench matters for regional safety

The Cotablet Trench, part of the Pacific Ring of Fire, has produced several destructive earthquakes in recent decades. Its location beneath the southern Philippines makes the archipelago especially prone to seismic shocks, a risk compounded by roughly 20 typhoons each year .

Experts note that the trench’s shallow depth in this event amplified ground shaking, increasing the likelihood of structural damage in coastal cities like General Santos. Ongoing monitoring will be crucial to assess whether further large‑magnitude events could arise from the same fault system.

Who remains unaccounted for after the quake?

While no fatalities have been confirmed, officials have not released a comprehensive casualty count. it is still unknown how many people may be trapped in the partially collapsed office building or other structures that suffered damage before office hours began.

Additionally, the full extent of infrastructure disruption—such as water supply, communications and transport links—has yet to be detailed by local authorities.