Large collapses on volcanoes have generated tsunamis, of which about 1% relates to volcanic collapse; both small collapses and earthquake-linked landslides that took place in historical times generated tsunamis. The 1998 Papua New Guinea earthquake in particular drew attention to this hazard. The most recent such tsunami is the 2018 Sunda Strait tsunami, which was caused by a flank collapse of Anak Krakatau and caused at least 437 fatalities. The possibility of a large collapse of this volcano causing a tsunami was known already before the 2018 event.