Twenty-seven thousand people died in a huge tsunami that swept over the seaport of Kamaishi, Japan, on June 15, 1896.
A local earthquake cause mild shaking of the port city, which was not unusual in this tectonically active area. However, twenty minutes later the bay began to recede, then forty-five minutes after the earthquake, the port city was inundated with a ninety-foot-high wall of water that came in with a tremendous roar. The town was nearly completely obliterated, and 27,000 people perished in a few short moments. Kamaishi was a fishing port, and when the tsunami struck the fishing fleet was at sea and did not notice the tsunami, since it had a very small amplitude in the deep ocean. When they sailed through many miles of debris and thousands of bodies, and reached their homes only to find a few smoldering fires among a totally devastated community.
"Fishermen twenty miles out to sea didn't notice the wave pass under their boats because it only had a height at the time of about fifteen inches. They were totally unprepared for the devastation that awaited them when they returned to the port of Sanriku. Twenty-eight thousand people were killed and 170 miles of coastline were destroyed by the wave that had passed under them."
From "The Physics Behind the Wave."
"On June 15, 1896, nearly 22,000 Japanese lost their lives due to the most devastating tsunami in Japanese history. The tsunami, which was generated by an earthquake off the coast of Sanriku, Japan, attained a height of 25 meters (80 feet), and instantly swept away all houses and people when it reached land. The tsunami was also observed across the Pacific. In Hawaii, wharves were demolished and several houses were swept away. In California, a 9.5 feet wave was observed, according to the San Francisco Chronicle of June 16, 1896. This Sanriku tsunami served as an impetus for tsunami research in Japan. "