"Oct. 17, 2015, Taan Fjord, Icy Bay, Alaska. The friction that held silt to silt and rock to rock began giving way. Those first rocks shoved more rocks, and then more still. Some 200 million metric tons of rock slid down the mountain in a crash that must have been deafening. It hit the ocean, sending up a wave that peaked at nearly 600 feet high. The wall of water stripped alder thickets from the hillside, tossed boulders up hills and carpeted the land in rubble from the bottom of the ocean.
No one noticed."
Read more here: adn.com/alaska-life/we-alaskans/2016/09/11/collapsing-alaska-mountains-southeast-alaska-landslides-and-tsunamis-on-the-rise/