Homework: Who was most directly responsible for the Deepwater Horizon Disaster? What Would be "Justice" for the Responsible Party?

Who do you think was most directly responsible for the Deepwater Horizon disaster? Why?--
I think that the crew was most directly responsible for the Deepwater Horizon disaster.  The crew was directly responsible for the disaster because they were the ones who initially got the reading that something was wrong but ignored it.  There were things that could have been done to prevent it and they were not.

What would be "justice" for the responsible party?
Justice for the responsible party can not properly be served.  Now although the crew was responsible, 11 people died, and others were injured so the sympathy part of me says that they should not be responsible for the justice.  The people who would be responsible for the justice would be the company and people that make the regulations because there should have been regulations that keep things like misreadings from happening.