Indonesia had the most deaths from the 2004 Indian Ocean tsunami. The earthquake struck offshore from northern Sumatra on 26 December 2004, and Indonesia—especially Aceh—was closest to the rupture and suffered the greatest destruction.
The magnitude 9.2–9.3 undersea megathrust earthquake displaced the seafloor and sent tsunami waves across the Indian Ocean. Indonesia’s final death toll is commonly estimated at around 170,000, within a total of roughly 228,000 fatalities across 14 countries. Many victims were killed in coastal communities around Banda Aceh and western Sumatra.
Sri Lanka, India and Thailand also suffered enormous losses, which can make the answer confusing. Thailand’s resort areas received extensive international coverage, while India and Sri Lanka had high casualties along their coastlines. The disaster is also called the Boxing Day tsunami because it occurred on 26 December, the holiday known as Boxing Day in many Commonwealth countries.