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This is the final highway accident report (NTSB-HAR-71-1) from the National Transportation Safety Board, adopted in December 1970. It covers the collapse of the U.S. 35 bridge between Point Pleasant, West Virginia, and Kanauga, Ohio, on December 15, 1967, which killed 46 people. The Board found that the cause was a cleavage fracture in eyebar 330 at joint C13N. That fracture grew from a flaw produced over 40 years by stress corrosion and corrosion fatigue, in a spot that could not be seen or found by inspection.
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## B. FIELD INVESTIGATIONS SINCE SEPTEMBER 1968 ## 1. Further Examinations at Reassembly Site Adequate answers to the question of whether there had been fractures in the stiffening truss or the hanger system which could have preceded the brittle fracture in eyebar No. 330 required the completion and detailed inspection of the two-dimensional reconstruction of the bridge at the reassembly site. This work was carried on by the West Virginia State Road Commission until October of 1968, resulting in the identification and placement of approximately 90 percent of the eyebar chains and 70 percent of the stiffening trusses, plus the principal elements of the Ohio and West Virginia towers. In September of 1968 a special team of the staff of the Office of Research of the Federal Highway Administration and representatives of Robert A. Hechtman and Associates, consultants to the Federal Highway Administration, took over operations at the reassembly site in order to complete as much additional identification and placement work as possible and to document all significant fractures for the record. This work was completed in October 1969 with approximately 90 percent of all available wreckage identified and placed. The detailed inspection of fractures resulted in the correction of a number of previous identifications. When layout was completed, a special series of low altitude vertical photographs were taken of the entire reassembly from a boom supported platform. These photographs were taken from positions about 30 feet above the ground and at a spacing such that an overlap of adjacent photographs of approximately 40 percent was obtained. In addition, all the fractures in the main chord members of the trusses were photographed at close range from two or more directions to document their features for the record. Each fracture was inspected to determine whether it was predominantly a cleavage fracture or a shear fracture, and where cleavage fractures were found, a careful inspection was made to determine whether there was any indication of a pre-existent defect. At the time of these inspections, a considerable accumulation of rust had formed on the fracture surfaces so that it was not possible to make positive judgments on the existence of such prior defects by field examination. In view of this condition, a program of additional laboratory samples was established, in which the ends of members containing fractures of special interest or those in which it was deemed there was a possibility of a pre-existent defect were burned off and shipped to the National Bureau of Standards for cleaning and metallurgical examination. The documentation work done at the reassembly site during this period is contained in Reference 7, excerpts of which are presented in Appendix A. The principal exhibit of this appendix consists of a
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