On December 15, 1967, at 4:58 pm, the 39-year-old Silver Bridge suddenly collapsed into the Ohio River during heavy rush hour and holiday season traffic, and forty-six lives were lost. The collapse was caused by a single hairline crack in a steel eyebar in the northern suspension chain. In response, Congress established national bridge inspection standards, creating a rigorous nationwide bridge safety inspection program to detect unsafe structural conditions, prevent future tragedies, and save countless lives.