the plane lost pressure but made a successful landing. southwest has been scrambling to inspect dozens of aging boeing 737s, 300 in its fleet. investigators have found cracks in three planes so far. joining us now is the former managing director of the national transportation board. how worried should we be and a lot of people are worried out there. >> boeing and ntsb are on this and in the air that it ripped off. >> who made a blunder that allowed a plane so vulnerable to -- that could have been horrendous disaster, who screwed up? there must have been a failure.