Would it have failed if it was properly maintained?
I bet somebody knows this. And that is the question that imposes culpability, not the ones you asked.
But if you are not going for culpability and just assumes everybody is honestly trying to improve, the question to ask is "was it properly maintained?"
Infrastructure needs maintenance, culpability only makes sense if there are enough funds for such maintenance and if there is an organization level compatible with the kind and scope of the work. I wouldn't make any assumptions about that in the case of Lybia.
I bet somebody knows this. And that is the question that imposes culpability, not the ones you asked.
But if you are not going for culpability and just assumes everybody is honestly trying to improve, the question to ask is "was it properly maintained?"