On December 26, 2004, just before 8 a.m., a 9.1-magnitude undersea earthquake struck 150 miles (240 kilometers) west of Sumatra, Indonesia, releasing energy equivalent to 23,000 atomic bombs, the BBC reports.
The tsunami waves generated by the quake traveled across the Indian Ocean at speeds of up to 800 kilometers per hour (the same speed as a jet plane). This tsunami became one of the largest natural disasters in modern history.
According to the US National Oceanic and Atmospheric Administration (NOAA), this earthquake was recorded in the record books and is the third strongest in the world since 1900.
The tremor was felt not only in Indonesia, but also in Bangladesh, India, Malaysia, the Maldives, Myanmar, Singapore, Sri Lanka and Thailand.