In the open ocean, tsunamis seem small and harmless. But a whole column of water is moving, measuring many miles to the ocean floor. By the time a tsunami reaches the shore, it transforms into a monster! With waves that can reach over 50 feet, a tsunami can level houses like a bulldozer, toss cars like toothpicks, and destroy everything in its path. Learn all about the world's deadliest tsunamis and what to do to keep safe if you ever encounter one.