What was the biggest event in 2004?

One of the biggest events in 2004 was the Indian ocean earthquake and tsunami, which struck on December 26. This devastating natural disaster resulted in over 230,000 deaths across multiple countries, including Indonesia, Sri Lanka, India, and Thailand, and caused widespread destruction. The tsunami prompted a massive international humanitarian response and raised awareness about disaster preparedness and response mechanisms. The event had long-lasting social, economic, and environmental impacts on the affected regions.