The earthquake that caused the 1960 tsunami occurred off the west coast of South America and had a magnitude between 8.25 and 8.5. The waves reached the Hawaiian Islands in about 15 hours. This tsunami caused little damage elsewhere in the islands, but the Hilo Bay area was hard hit. 61 people lost their lives and about 540 homes and businesses were destroyed or severely damaged. The wave heights in Hilo Bay reached 35 feet, compared to only 3-17 feet elsewhere. The water washed far inland through the entire present downtown area.
This is a real, very real warning that I hope anyone in Hawaii takes action upon.