On 28 September 2018, a shallow, large earthquake struck in the neck of the Minahasa Peninsula, Indonesia, with its epicentre located in the mountainous Donggala Regency, Central Sulawesi.

The magnitude 7.5 quake was located 70 km (43 mi) away from the provincial capital Palu and was felt as far away as Samarinda on East Kalimantan and also in Tawau, Malaysia.

[14] The Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG) confirmed that a tsunami had been triggered, with its height reaching an estimated maximum of 4 to 7 metres (13 to 23 ft), striking the settlements of Palu, Donggala and Mamuju along its path.

[18][16] Sulawesi lies within the complex zone of interaction between the Australian, Pacific, Philippine and Sunda plates in which many small microplates are developed.

[10] The main active structure onshore in the western part of Central Sulawesi is the left-lateral NNW-SSE trending Palu-Koro strike-slip fault that forms the boundary between the North Sula and Makassar blocks.

[10] During the mainshock, the rupture propagated at speeds in excess of the S wave velocity as determined by back-projection of teleseismic data,[29] and supported by satellite geodesy.

[46] A 2019 research suggests the earthquake created about 1.5 meters of vertical seafloor movement, which, combined with a very fast rupture speed, could have produced the tsunami, regardless of any landslides.

[52] Palu's Mutiara SIS Al-Jufrie Airport was forced to close as large cracks, one of which was 500 meters long, had been formed on the runway.

[61] Communication to the affected area was severely hampered, with President Joko Widodo being initially unable to contact governor Longki Djanggola.

[62] Ministry of Communication and Information Technology announced that 1,678 base transceiver station in Central Sulawesi were damaged by the earthquake and disaster.

[65] An assessment made by the Ministry of Education and Culture showed that nearly 3,000 schools had been damaged by the earthquake and tsunami[66] and more than 100,000 students[67] and 20,000 teachers were affected.

[68] Minister of Education and Culture Muhadjir Effendi stated that a period of minimum 1 year would be needed to rebuild and repair the damaged schools in the affected areas.

[76] Indonesian National Board for Disaster Management announced that 2,050 houses were destroyed by the mudflow in Petobo and an area of 180 hectares were shifted by the liquefaction.

The liquefaction also reportedly managed to shift the overhead electrical tower in the area to several hundred meters from its initial position.

The Governor of Central Sulawesi Longki Djanggola agreed to build memorial parks in Petobo, Balaroa and Jono Oge to commemorate thousands of victims who were killed in the disaster.

The Vice President of Indonesia Jusuf Kalla announced the day after the disaster that the death toll will likely rise to more than a thousand, added that he based his statements on his past experience during the 2004 Indian Ocean earthquake and tsunami.

[86] On 30 September 2018, officials from the Indonesian National Search and Rescue Agency reported that at least 100 people were trapped inside Tatura Mall, the oldest and the largest shopping center in Palu.

The Head of Data, Information and Public Relations Center of Indonesian National Board for Disaster Management, Sutopo Purwo Nugroho, stated that around 2.4 million people were affected by the earthquake and tsunami.

[94] Reports from the city revealed that "dozens of people" were killed by the earthquake, including the 34 students from a Bible camp that died after being struck by a mudflow.

[105] Minister of Finance Sri Mulyani announced that the ministry would provide 560 billion rupiah for the recovery effort in Central Sulawesi.

[115] Ministry of Research, Technology, and Higher Education M. Natsir stated that every college students in Palu who were affected by the disaster would be given scholarship from the government.

[121] The local government of Lamongan, East Java, sent 34 trucks carrying more than 4,000 boxes of mineral water, 15.89 tonnes of rice, 2,000 packages of sembako, canned foods and other aids to Central Sulawesi.

[124] Local government of Boalemo Regency sent blankets, foods and other essential aids as well as medical team and SAR personnel to Palu and Donggala.

The Indonesian state-owned oil company Pertamina stated that many of their gas stations had run out of fuel due to the mass exodus.

As requested by the Indonesian Armed Forces (TNI), both aircraft will stay in Sulawesi to transport survivors to other cities of Indonesia that have better facilities to cope, as the tsunami destroyed much of the existing town.

Australian Foreign Minister Marise Payne stated that the $5 million will include emergency healthcare support in the initial phase up to 21 days.

[155] Saudi Arabian Ambassador to Indonesia, Osama Mohammed Al Shuaibi, stated that the Saudi Government has distributed 370 tons of basic necessities, 5,000 units of health equipment, and 3,500 tents for the earthquake and tsunami victims in Palu, noting that the aids were from King Salman bin Abdulaziz and Prince Mohammed bin Salman.

[157] Venezuelan President Nicolas Maduro announced that Venezuela would donate a total of $10 million in financial aid to the victims of the earthquake and tsunami, even though the country itself was facing a crisis.

[160] The Salvation Army's Indonesia Emergency Services Team was activated in response and worked to assess the damage and needs of those injured or displaced by the tsunami.

[161] The United Kingdom's defense secretary announced that they were to send a RAF A400M Atlas aircraft, a team of military experts, and HMS Argyll, and make £2m of aid available for the relief effort.