The bridge has two sections of roughly equal length ; the older western section , officially known as the Willie L. Brown Jr . Bridge ( after former San Francisco Mayor and California State Assembly Speaker Willie L. Brown Jr. ) , connects downtown San Francisco to Yerba Buena Island , and the newer unnamed eastern section connects the island to Oakland . The western section is a double suspension bridge with two decks , westbound traffic being carried on the upper deck while eastbound is carried on the lower one . The largest span of the original eastern section was a cantilever bridge . During the 1989 Loma Prieta earthquake , a portion of the eastern section 's upper deck collapsed onto the lower deck and the bridge was closed for a month . Reconstruction of the eastern section of the bridge as a causeway connected to a self-anchored suspension bridge began in 2002 ; the new eastern section opened September 2 , 2013 , at a reported cost of over $ 6.5 billion , a 2,500 % cost overrun from the original estimate of $ 250 million . Unlike the western section and the original eastern section of the bridge , the new eastern section is a single deck with the eastbound and westbound lanes on each side making it the world 's widest bridge , according to '' Guinness World Records '' , as of 2014 . Demolition of the old east span was completed on September 8 , 2018
1989 Loma Prieta earthquake
1989 Loma Prieta earthquake
San Francisco–Oakland Bay Bridge