Episode 1 of 2

1847 Zenkoji Earthquake Dam Failure

When
late May 1847, 19 days after 8 May
Where
Sai River
Part of
The 1847 Nagano earthquake kills thousands in Japan

A landslide dam on the Sai River failed 19 days after the earthquake, causing a flood that killed 35 people.

The earthquake triggered many landslides, the largest of which dammed the Sai River. 19 days later, the failure of this earthquake dam caused a flood that destroyed many more houses and killed 35 people.

Sources

  1. 1847 Zenkoji earthquake Wikipedia, revision of 2026-07-26

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.