An 9.1 magnitude earthquake struck off the coast of Sumatra, Indonesia on December 26th, causing a devastating tsunami. Over 200,000 people were killed as massive waves slammed into coastlines in 11 countries from East Africa to Thailand. The tsunami was so powerful because it was caused by an enormous underwater earthquake that displaced trillions of tons of rock and water. Many victims were caught unaware since there were no tsunami warning systems in place. One diary recounts a family's experience at a hotel in Indonesia when the earthquake and tsunami suddenly hit, expressing both fear and gratitude for the international aid that helped the victims.