as was the case with United Flight 232 that crashed in Sioux City, IA back in 1989.

"Investigators were able to recover the aircraft's tailcone as well as half of the fan containment ring. Also found were fan blade fragments and parts of the hydraulic lines. Three months after the accident, two pieces of the engine fan disk were found in the fields near where the first pieces were located. Together the pieces made up nearly the entire fan disk assembly. Two large fractures were found in the disk, indicating overstress failure. Metallurgical examination showed that the primary fracture had resulted from a fatigued section on the inside diameter of the disk. Further examination showed that the fatiguing had resulted in a small cavity on the surface of the disk, apparently a defect in manufacturing. The 17 year old disk had undergone routine maintainence and six times had been subjected to flourescent penetration inspections. Investigators concluded that human error was responsible in improperly identifying the fatigued area before the accident."

[Emphasis added] - Note how a small manufacturing defect took 17 years to cause the failure, but the end result was that 111 of the 296 people on board died. The fact that 185 people survived was due to the outstanding airmanship demonstrated by the crew.