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 (for a seismic retrofit of the existing span). 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.