The eruption of Krakatoa was a VEI-6 event that fundamentally altered the geography of the Sunda Strait. The explosion was so powerful it was heard 3,000 miles away. However, the most lethal aspect was the massive tsunami triggered by the caldera collapse and pyroclastic flows entering the ocean. The resulting waves obliterated nearly 300 coastal towns and villages. Beyond the immediate physical destruction, the eruption also had global atmospheric effects, injecting enough ash into the sky to create vivid red sunsets worldwide and lowering global temperatures by over 1°C for several following years.