all hell breaks loose

(idiomatic) The situation becomes chaotic or characterized by conflict or rage.

Example: 1667, John Milton, Paradise Lost:
  Came not all hell broke loose?
1992 August 19, “Beckel, Barnes and Rollins Discuss the Republican Convention”, CBS_Morning:
  I think it's kind of fun because, had Hillary Clinton spoken at the Democratic Convention, all hell would have broken loose.