The cause of the bhopal disaster?

Question

the bhopal disaster ...its causes ..the condition of the ppl..the situation at that time..

Answer 1

Somebody didn't turn off a valve.

Answer 2

When we have a situation that can cause a major disaster, we must know better than to depend on some human to take necessary action to prevent that disaster. We must build the system redundantly fail safe.

There is nothing inherently wrong with having the system open to human intervention if there are checks to see that this human intervention will not be disastrous. But  we can not build systems as critical as this with a necessary human intervention which may never come.