Dow Chemical Company maintenance personnel know the importance of mechanical integrity for their industrial safety programs. But the $57 billion enterprise experienced a significant “near-miss event” at one of its facilities caused by lapses in understanding by local personnel of corrosion under insulation (CUI). On March 13, 2008, at a Dow LHC plant, an 8 inch, schedule 20, carbon steel hydrocarbon line failed. The event began with a small pinhole leak, detected by the operators. Then while they were isolating and de-pressuring the line, it failed catastrophically. Fortunately, this failure produced such explosive force that the line bent in two locations – essentially sealing itself and avoiding a major release and potential loss of life. The cause? CUI, which provided a number of valuable lessons for inspection personnel and Dow managers.