You didn't exactly answer my question Balance. With the benefit of hindsight, it's not hard to see how the things you mention could have added up to a disaster. However, if you, or anyone else with concerns, had publicly warned of the likelihood of an explosion, then maybe - if anyone in power had acted - this tragedy could have been averted.
Regardless of any shortcomings within management, had government provided the advisorial and inspectorial role expected of it, safety problems would have been addressed early on. The buck should stop at the top, but seldom does.
The failure of successive governments to protect their citicizens has been evidenced in huge loss of savings, and in some cases lives, through deregulation in the building (leaky homes) and finance industries, adventure tourism, and now mining, to name a few. Wonder what will be next !