This document summarizes key details about the devastating 2011 Tōhoku earthquake and tsunami in Japan. It reports that the 8.9 magnitude earthquake was the most powerful to hit Japan on record and triggered a massive tsunami. Over 15,000 people were killed and hundreds of thousands were evacuated. Infrastructure damage is estimated at over $100 billion and radiation levels inside the damaged Fukushima nuclear power plant exceeded normal levels by 1,000 times. International assistance for relief efforts was pledged by over 100 countries.