What exactly caused Chernobyl?

Related questions

1. Why is Fukushima radioactive?
2. How does an RBMK reactor explode?
3. How long does radiation take to kill you?
4. What would happen if a nuclear reactor exploded?
5. How does an RBMK reactor work?
6. Is it safe to go to Fukushima?
7. Are the reactors in Chernobyl still active?
8. Is Fukushima still evacuated?
9. What does the moderator do?
10. How does a graphite moderator work?

Tags

1. #inadequately
2. #flawed
3. #reactor
4. #radioactive
5. #downwind
6. #released
7. #fires
8. #least
9. #design
10. #explosion
11. #steam
12. #trained
13. #accident
14. #resulting
15. #result
16. #chernobyl
17. #operated
18. #atmosphere
19. #personnel