What is survival mode in fallout shelter?

Related questions

1. How do you survive fallout shelter?
2. How do you start over in fallout shelter?
3. Do dwellers die of old age?
4. Can you breed pets in fallout shelter?
5. Do dwellers heal over time?
6. How do you turn on survival mode in fallout shelter?
7. Can Mr Handy regenerate health?
8. What does Mr Handy do in fallout shelter?
9. What does Nuka Cola bottler do?
10. Where is my Mr handy in fallout shelter?

Tags

1. #harder
2. #incidents
3. #frequently
4. #reviving
5. #vaults
6. #significantly
7. #consumed
8. #symbol
9. #resources
10. #marked
11. #death
12. #faster
13. #version
14. #occur
15. #radiation
16. #dweller
17. #permanent
18. #vault
19. #survival
20. #tougher