The Great Storm

The Great Storm took place in Bramblestar's Storm, when the lake flooded, and caused the death of many cats, as well as a need to leave their camps.

To the Tunnels!
When the lake floods and the dens get destroyed, Bramblestar leads Thunderclan into the tunnels and they make their home there temporarily until the water goes down so they can return and repair their home.

Blackstar's Death
Blackstar loses his last life due to drowning in the great storm and Rowanstar becomes the new leader of Shadowclan.