The 2018 Central Sulawesi earthquake and tsunami have sparked off a serious debate on the efficacy of the Indonesia Tsunami Early Warning Systems (InaTEWS). The 'cascading disasters' suggest an apparent failure of early warning chain and technological deficiencies that resulted in a heavy death toll. This article examines how factors beyond technological aspects such as socio-cultural factors and local memories of past disasters play a significant role in mitigating communities against disasters. Methodologically, this paper followed a qualitative approach based on in-depth interviews and direct observation to develop arguments. Findings show that tsunami risk perception, local belief, and faith affected community response capacity. Besides, lack of education in disaster preparedness, coupled with ignoring history of tsunamis, limited the ability of people to react appropriately when disasters unfolded. However, in the absence of an alert system, the coastal community in Donggala demonstrated the best practice of tsunami preparedness by harnessing local knowledge. The community in Donggala has been preserving the tsunami memories from 1938 and 1968 through oral transmission across generations about bombatalu or lembotalu (three waves) stories. In conclusion, this paper recommends a people-centred approach to the Indonesia Tsunami Early Warning Systems (InaTEWS) against disasters in the future.