What is an interesting, lesser known historical event from the 20th century?

Have an essay due for my World History class and I can pick a topic. I am interested in a lot of things, so it’s been difficult to choose. Another thing making it difficult is that we’re not allowed to do anything involving things we talked about in class. That being said, here are the topics that are off-limits:

WWI AND WWII

Russian Revolution

The Cold War (which includes Cuban Missile Crisis, Vietnam War, Korean war, etc.)

Post-WWI peace treaties

Pre-WWII politics (Hitler coming into power, etc.)

Economics and depressions

Israel/Palestine conflicts

Some of my ideas so far:

How safety evolved throughout the century (labour laws, lead and asbestos, seatbelts)

Molasses flood

Emu war

Historical mysteries (however a lot of the interesting ones are related to the world wars)

Radium Girls

Any ideas are welcome, thanks so much!