Here are some of the biggest disasters in Attack on Titan history:
Choose to save Armin or Erwin
The decision to inject Titan spinal fluid to save Armin or team leader Erwin caused debate within the scout team.
Attack on Utgard

When Zeke’s giants pressed their scouting force into Utgard, it led to a desperate bid for survival.
The massacre of the royal family

Grisha Yeager understood the royal family’s indifference to Paradis’s plight and begged them to reconsider.
The first attack on Shiganshina

The first attack on Shiganshina is the source of the entire story of Attack on Titan.
The Battle of Liberio

As soon as Willy Tybur declared war on Paradis, he was tragically killed by Eren (Titan Tien Cong) from behind the stage, along with many people in the wings and audience below.
The massacre at Liberio was a serious disaster for Marley and Paradis.
Zeke poisons the people of Paradis

Zeke has carefully hatched a sinister plan to usurp rule over the Eldian people.
Vibration
After fully unlocking the power of the Founding Titan, Eren unleashed Tremors, bringing destruction to hundreds of massive Titans.
Before being stopped by Armin’s group, Eren and Rung Chan destroyed 80% of the world’s population in just a few short days.