A tsunami begins as an unseen disturbance deep in the ocean and ends as a wall of water capable of flattening a coastline in minutes. This episode of the Fatal Forecast series centers on the 2018 Palu tsunami in Indonesia, using it as a case study to examine how such waves form, why they are so hard to predict, and what warning systems failed or succeeded that day. Scientists and disaster experts walk through the mechanics of undersea earthquakes and landslides that trigger tsunamis, footage and survivor accounts convey the scale of the destruction in Palu, and the film weighs current forecasting technology against the speed at which these waves actually strike. The throughline is practical rather than sensational: what real-time data, buoy networks, and evacuation planning can realistically do when a coastal population has only minutes to react. It closes on the gap between existing prediction science and the lives lost when warnings arrive too late.