Deadly waves in the form of tsunamis have become one of the most terrifying natural phenomena in the world. A tsunami is a large ocean wave caused by underwater movements, such as earthquakes, volcanic eruptions, or underwater landslides. This definition includes various aspects that make it more than just a big wave. One of the main causes of tsunamis is earthquakes that occur on the seabed. When tectonic plates move, the energy released can trigger giant waves. For example, the earthquake that occurred in the Indian Ocean in 2004, which had a magnitude of 9.1 on the Richter scale, produced a tsunami that killed more than 230 thousand people in dozens of countries. Waves reaching a height of 30 meters devastated coastal areas and changed the lives of millions of people. Volcanic eruptions can also trigger tsunamis. When a volcano erupts, material that falls into the sea can cause large waves. A famous incident was the eruption of Krakatoa in 1883, which created a tsunami up to 40 meters high and caused more than 36,000 deaths. Tsunamis are also different from ordinary waves. While sea waves are generated by wind and tend to be low, tsunamis have very large wave lengths, up to hundreds of kilometers, and speeds can reach 800 km/hour. Upon arrival at the beach, this energy accumulates, so that its height can reach tens of meters. The region most prone to tsunamis is the “Pacific Ring of Fire,” which surrounds the Pacific Ocean and is known for its high seismic activity. Countries such as Japan, Indonesia and Chile often face the threat of tsunamis. Japan, in particular, has a sophisticated early warning system and evacuation routes to minimize loss of life. Coastal communities also need to be sensitive to the signs of a tsunami. A sudden drop in sea level, roaring sounds, or strong vibrations are indications that a tsunami may be coming. Education and evacuation drills are important to reduce the risk of this disaster. To overcome the impact of the tsunami, various modern technologies have been developed. Tsunami detection and warning systems use underwater sensors to detect waves and send warnings to areas at risk. Apart from that, engineering and design of tsunami-resistant building construction also plays a role in saving lives. Nature-based approaches, such as mangrove planting, also contribute to coastal protection. In recent decades, attention to tsunamis has increased. Scientific research helps understand tsunami patterns and behavior, which is important for disaster mitigation. International programs focus on research, education, and policy development to improve tsunami preparedness. Finally, although tsunamis are a deadly natural phenomenon, joint efforts from governments, communities, and scientists can help reduce risks and improve safety. The tsunami brought an important message about the power of nature and the need to respect and prepare for its power.