Why did Fukushima explode?

Related questions

1. Has the US ever been in Defcon 1?
2. What is Defcon CTF?
3. What is a flag in CTF?
4. What is the current threat level?
5. How do you play Blob Tag?
6. How does capture the flag work?
7. What are the rules of tag?
8. What is a capture the flag event?
9. What Defcon is the United States at?
10. What is Jeopardy style CTF?

Tags

1. #causing
2. #supply
3. #accident
4. #largely
5. #nuclear
6. #tsunami
7. #march
8. #fukushima
9. #power
10. #cooling
11. #cores
12. #following
13. #major
14. #daiichi
15. #three
16. #first
17. #earthquake
18. #metre
19. #reactors
20. #disabled
21. #melted