I agree that cockpit doors should have been secured long before 9/11 but I don't see how the airlines can be held responsible for ignoring a threat of which they were not aware. However, numerous government agencies did have information about the 9/11 terrorists long before they arrived at the airports. They were also well aware of Umar Farouk Abdulmutallab months before he was escorted onto the plane in Amsterdam. So I'm at a loss here as to why blame is being laid at the feet of the airlines.