The document discusses the tsunami warning system in the Indian Ocean. It describes the old warning system which lacked coordination between countries. It then discusses the devastating 2004 Indian Ocean tsunami that killed over 230,000 people and led to improvements like more sea level monitors and better international communication. Now two main warning centers, the Pacific Tsunami Warning Center and Japan Meteorological Agency, analyze earthquakes and predict potential tsunami impacts, alerting countries within 20 minutes through radio, TV, internet, sirens and other means.