December 26, 2004, at 7:58 am local time (0:58 UTC), a major earthquake of magnitude 9.1 occurred off the eastern coast of Sumatra, Indonesia, and generated a tsunami that killed at least 225,000 people across a dozen countries, with Indonesia, Sri Lanka, India, Maldives, and Thailand particularly badly hit (see also Section 9.1). The tsunami was recorded by tidal gauges not only in countries facing the Indian Ocean but also in Antarctica, Japan, and others. Many countries facing the Indian Ocean lost many of their citizens due to the tsunami flooding, which took the inhabitants of coastal areas by surprise due to both a lack of awareness and warning (given that there was no ground shaking to alert them).