One person wrote:

3. the simplest answer to the extinction of many dinosaurs is the worldwide flood in the time of Noah. Chris has posted that in the Pacific that is described as a Tsumi wave (sorry, I can’t visualise the word just now) – and in time that could have become the given event as the locals used a local occurrence to describe what had happened

Another (better informed) person responded:

At some time over the past year (sorry, I can’t remember just when) I responded to a claim about flood stories being widespread. I commented that many of these stories from the Pacific and surrounding areas spoke about rising waters, but made no mention of rain. I suggested that these stories were much more compatible with memories of a tsunami than of a world-wide (in the modern sense) flood.

Let me add in passing that flood stories are notable by their absence in very mountainous areas.

And since many people living at near sea-level build their settlements beside rivers, it’s perfectly understandable that there would be floods – and quite large floods, too. The Brisbane flood of January 1974 was described as a “once in a hundred years flood”, which is frequent enough to be incorporated into the folk-tales of society.