Gang forces have revived, raising grave concerns about public safety.
Tips
history
From the 《史记·韩长儒列传》: when jailer Tian Jia humiliated Han Anguo, Han replied 死灰独不复燃乎?- 'Won't the dead ashes ever burn again?' Later, restored to power, he proved the point. Originally hopeful, it became overwhelmingly negative.
usage
Almost always negative - describes the unwanted return of bad things: diseases, corruption, gangs, old enmities, failed ideas. Rarely used for positive comebacks.