The opening of the San Francisco - Oakland Bay Bridge in 1936, and the Golden Gate Bridge in 1937, forever changed the Bay Area's economy and transportation habits by allowing easier travel and access to new places for work and recreation. The Bay Bridge consists of two bridges: an eastern span between Yerba Buena Island and Oakland and a western span between the island and San Francisco. The pier is built on pilings that once supported the original eastern span. The 1989 Loma Prieta Earthquake caused part of the upper eastern span deck to fail, highlighting the danger that a 6.9 earthquake centered sixty miles away could cause and raising concern about the larger 7.3 magnitude earthquake predicted possible on the Hayward Fault only six miles away. After many years of planning, a new seismically secure suspension bridge for the eastern span was built between 2002 and 2013 at a cost of about $6.5 billion, far above the original estimate of $250 million. More than 100 million vehicles now cross this iconic landmark each year.
