Incident

Incidents are a game mechanic in Fallout Shelter.

Gameplay
Incidents can happen randomly, or when the rushing of a room fails. Incidents need to be dealt with quickly by dwellers or they will spread to adjacent rooms. During an incident, dwellers in the same room are damaged and will not produce anything until the incident has been resolved.

Possible incidents include radroach, mole rat and radscorpion infestations, fires, and raider, feral ghoul or Deathclaw attacks.