Burn itself out
Definition 1 of 2
Pro Tip 1/3Natural Conclusion
This phrase implies an event ending naturally without external interference. 
The heated debate finally burned itself out after hours of discussion.
Pro Tip 2/3Not Instant
The process involves gradual depletion of energy or resources over time. 
The hurricane raged for days before it finally burned itself out.
Pro Tip 3/3No Human Control
It suggests lack of human control over the ending of an event or situation. 
Despite everyone's concerns, the festivities burned themselves out as participants grew tired.