Bay Bridge

The San Francisco-Oakland Bay Bridge is a complex of bridges spanning San Francisco Bay in California, carrying approximately 260,000 vehicles daily on its two decks. It was designed by Charles H. Purcell and built by American Bridge Company, opening on November 12, 1936, six months before the Golden Gate Bridge. The bridge originally had separate decks for automobile and rail traffic, but was converted to all-road traffic in 1958. In 1986, the bridge was unofficially dedicated to former California governor James Rolph. A significant section of the bridge collapsed during the 1989 Loma Prieta earthquake and was rebuilt as a causeway connected to a self-anchored suspension bridge at a cost of over $6.5 billion. The original estimate for the reconstruction was $250 million for a seismic retrofit.learn more on wikipedia