The San Francisco-Oakland Bay Bridge's eastern span replacement, completed in 2013, is an engineering marvel and the world's widest bridge. Designed to withstand earthquakes, the $6.5 billion project involved innovative techniques like the self-anchored suspension (SAS) bridge design and earthquake-resilient features. Despite its impressive engineering, the project faced controversies over cost overruns, defective welds, and construction flaws. Initially estimated at $250 million, the final cost skyrocketed due to significant design changes and seismic safety measures.