WhereIsAtlas · Indonesia

What Happened in the Central Sulawesi Disaster?

The 2018 triple disaster that hit Palu — a magnitude-7.5 earthquake, a tsunami, and ground liquefaction in a single catastrophic event.

On 28 September 2018, a magnitude 7.5 earthquake struck Central Sulawesi, triggering a tsunami and devastating liquefaction in Palu. The triple disaster killed more than 4,000 people, making it one of the deadliest events in Indonesia's modern history.

A triple disaster

On 28 September 2018, a magnitude 7.5 earthquake struck off the coast of Central Sulawesi, Indonesia. But the earthquake itself was only the first of three devastating hazards.

The tsunami

The quake triggered a tsunami that swept into the city of Palu and the nearby districts of Sigi and Donggala. The waves arrived quickly, striking low-lying coastal areas with devastating force.

Liquefaction: the invisible killer

What made the disaster so destructive — and so scientifically notable — was liquefaction. When the saturated ground beneath parts of Palu shook, it began to behave like a liquid. Under the settlement, the earth subsided and slid, and entire neighborhoods were swallowed or shifted in a single catastrophic movement. It was a rare and terrifying demonstration of what happens when the ground itself turns against those who stand on it.

The toll

The triple disaster — earthquake, tsunami and liquefaction — caused massive destruction and killed more than 4,000 people. It was one of the deadliest events in Indonesia's modern history, and the toll in Palu and its surroundings was catastrophic.

The lesson

The 2018 Central Sulawesi disaster is a case study in how a single earthquake can set off multiple, compounding hazards. It is a grim reminder that in an earthquake-prone archipelago like Indonesia, the danger is not just the shaking — it is everything the shaking can unleash afterwards.

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