What is the worst thing that happened in the history of the world?

Answer 1

Either World War 1, World War 2, or the atomic bombs in Japan.

2nd Answer:

WW I and the bombs were nothing compared with other world disasters. Here are a few:

1. The Black Death, starting in year 1330, killed 75 million people: far, far more than were killed in WW II.

2. Stroggli Island explosion in 1551 BC, was a volcanic event that made the entire Medi terranean island disappear, and caused the entire Minoan Civilization to be wiped out.

3. The Yangtze River flood in 1931 killed 3.5 million people, and injured or made homeless at least 51 million more.

4. The Cretacious-Paleogene extinction, likely caused by an asteroid's impact with the Earth 66 million years ago, wiped out all of the non-flying dinosaurs, and at least 75% of other land, air, and ocean animals, along with plant life that they might have survived on by eating them.