Tsunami.
Recently we observed the tsunamy in Indonesia. The height and speed of the tsunami waves were very large. This time was a storm at sea. The strong wind blew. The tsunami hit the coast with great force. All buildings on the coast were destroyed. Many people died after the tsunami.
Natural cataclysms are unpredictable. People suffer from natural disasters. I think that thunderstorms are the most dangerous. It is a storm with thunder and lightning and very heavy rain. Such rain can lead to floods. Lightning can also lead to fires. Nowadays, weather services can provides forecast and people may know about this cataclysm in advance.
