Large landslides are part of the evolution of each Hawaiian island.
As the landslides move they probably generate large earthquakes that would be felt across the island and probably across the state. Part of the volcano and everything on it would disappear below sea level. Since the landslides are so large they would displace great volumes of water and generate a tsunami far larger than any ever observed. There are coral deposits about 1,000 above sea level in Hawaii that were placed there by tsunami waves. Geologist is Australia proposed that a tsunami from Hawaii striped about 50 feet of beach sand from the coast about 100,000 year ago.