So tsunamis are definitely a threat generally from earthquakes and an earthquake of this size can make it deadly. Unlike the San Andres faults that cause most California earthquakes ( which wouldn’t produce significant tsunamis) this earthquake occurred in a discordant part of the pacific oceanic crust called the Mendocino triple junction - the intersection of the San Andres fault, Cascadian subduction zone (where the Pacific crust is plunging under the North American continent, feeding features like Mt. St Helens), and the Gorda plate (the last remnant of the precursor to the pacific plate, the Panthalassic Ocean that surrounded Pangea).

Because there’s a Wikipedia article for everything, if anyone else is morbidly curious about the history of dying on stage