A large landslide in Alaska’s Tracy Arm fjord is reported to have generated a major tsunami. Multiple reports describe a slope failure above the fjord on 10 August 2025, when about 64 million cubic metres of rock fell into the remote Tracy Arm area near the South Sawyer glacier. The rockfall produces a seismic signal, with one account describing a 5.4 magnitude event associated with the landslide. Researchers also characterize the resulting wave as a “megatsunami,” linking the scale of the landslide volume to unusually large wave heights. One outlet reports an especially extreme maximum wave height, describing a tsunami reaching up to 481 metres, while another focuses on the landslide’s volume and the resulting megatsunami in the fjord. Both accounts treat the rockfall and the tsunami it generates as part of the same event and place the occurrence in the Tracy Arm fjord region in August 2025. The reports synthesize observations and analyses suggesting the fjord setting and the size of the collapse play a key role in producing very large waves.