Did you know that tsunamis, series of ocean waves usually caused by an earthquake, can travel as fast as a jet plane? On March 11, 2011, the fourth most powerful earthquake in the world shook the earth 43 miles east of the northeast coast of Japan’s main island. The Richter scale is used to measure how strong an earthquake is, and this earthquake measured 9.1, which caused tsunami waves as tall as 133 feet—that’s as tall as a fourteen-story building!

Even though it’s water, the force of such a tsunami, which becomes as hard as a hammer, can knock down three-story buildings and sweep up cars. In the 2011 episode, 20,000 people died, 6,000 people were injured, 2,500 people were never found, and 250 miles of coastline dropped by two feet.

Hundreds of thousands of people were left homeless and had to live in shelters, such as school gyms. Today, over 100,000 of those people have never been able to go home and still live in temporary houses, which are tiny metal cubes. Always take tsunami warnings seriously.