Early on in the saga of why a Southwest jet lost a piece of its roof in flight on April 1, I mentioned here that sometimes things happen to airplanes that are completely unanticipated, even when airplane makers and airlines try to cover all the bases and do a decent job of avoiding trouble spots. That seems to be emerging in this case, with the discovery of possible manufacturing errors to the jet in question.
In a story first reported by ABC tv news last week, the National Transportation Safety Board's preliminary assessment of why the Southwest 737 suffered the near-catastrophic accident, 34,000 feet over Arizona points to rivets and how they were installed. There appears to have been sloppy riveting work done in the original manufacturing of the 15-year-old jet at a Boeing Co. plant where the wings were made. Here is a good story on what the NTSB has found in its ongoing investigation.