The underwater volcanic eruption near Tonga sparked a monster tsunami of nearly 300 feet waves, scientists believe.
It was big enough to cover a 25-storey building.
Despite this, only three people died as waves hit Tonga.
They based their findings on computer simulations.
Scientists think it was the largest wave since the infamous Krakatoa eruption of 1883 in Indonesia.
While that event had major global impact, the Tonga eruption was fortunately less damaging.
“The main factors, we suggest, are the quirk of the location and increased evacuation drills and awareness efforts,: said Professor Sam Purkis, of the University of Miami.
