 The tsunami struck Higo Province on the other side of Ariake Bay before bouncing back and hitting Shimabara again.Out of an estimated total of 15,000 fatalities, around 5,000 are thought to have been killed by the landslide, around 5,000 by the tsunami across the bay in Higo Province, and a further 5,000 by the tsunami returning to strike Shimabara.The waves reached a height of , classing this tsunami as a small megatsunami.