General Chaos:
* Disorder
* Turmoil
* Uproar
* Confusion
* Disarray
* Pandemonium
* Mayhem
* Bedlam
* Hullabaloo
More Intense or Violent Chaos:
* Carnage
* Ravages
* Desolation
* Ruin
* Anarchy
* Breakdown
More Abstract or Philosophical Chaos:
* Disintegration
* Entropy
* Randomness
* Uncertainty
* Instability
Informal or Humorous Chaos:
* A mess
* A free-for-all
* A zoo
The best word to use will depend on the specific context of your writing.