As the first U.S. Navy base established on the Pacific Ocean, Mare Island Naval Shipyard was founded in 1854. It is situated 25 miles northeast of San Francisco in Vallejo, California. The shipyard closed in 1996. In 1960, it was registered as a California Historical Landmark, and parts of it were declared a National Historic Landmark District in 1975. Nevertheless, people who worked at Mare Island Naval Shipyard were exposed to asbestos to a great extent, as the mineral was crucial for building military vessels. Aboard every ship, there were more than 300 asbestos products that endangered the health of military members. Shipyard workers inhaled the largest amounts of asbestos when installing asbestos insulation, as it would release a lot of toxic dust into the air.