The Richmond-San Rafael Bridge opened to traffic in 1956 after 2 years of planning and design and 4 years of construction. Its 4.5-mile length and double-decker design made it one of the most complex bridges in the state and California’s longest steel structure at the time. It serves as a vital link between Marin and Contra Costa Counties, and more than 75,000 commuters use it daily to cross the northern end of San Francisco Bay. After the October 17, 1989, Loma Prieta Earthquake, which measured 7.1 on the Richter scale and lasted 15 seconds, California reviewed the seismic safety of its bridges, including this one. Situated between the San Andreas Fault 10 miles to the west and the Hayward Fault 4 miles to the east, the nearly 50-year-old bridge was retrofitted under a no collapse criterion so it could withstand a 7.25-magnitude earthquake on the Hayward Fault and an 8.0-magnitude earthquake on the San Andreas Fault. The retrofit strengthened the bridge from its foundations and deck to its steel towers and trestle. Workers faced strong currents, high winds, and little to no underwater visibility as they installed large-diameter piles between the bell-shaped foundations of 11 piers, while 47 piers received micropiles drilled through existing foundations, with 480 micropiles installed in all. The project also added modifications for controlled movement during earthquakes, including viscous dampers at the towers’ anchorages that allow the bridge to expand or contract by as much as 6 feet to absorb seismic energy and reduce structural damage, along with isolation joints and bearing that further strengthen the main structure.