2004 Indian Ocean tsunami: What to know 20 years on

The 20th anniversary of the devastating 2004 Indian Ocean tsunami approaches, commemorating over 220,000 lives lost across a dozen countries. Triggered by a 9.1 magnitude earthquake off Sumatra, the tsunami's immense waves, reaching over 30 meters, caused widespread destruction. The disaster prompted a global effort in reconstruction and the development of crucial tsunami warning systems.