USS Gridley (DLG-21) the "Spruance"-class destroyer to escort reflagged Kuwaiti oil tankers through the Strait of Hormuz during Operation Earnest Will. While homeward bound, transiting the South China Sea, "Gridley" rescued Vietnamese refugees sighted in a small boat off of the coast of Vietnam. A Vietnamese-speaking crewman aboard "Gridley" was able to translate for those rescued, facilitating the process. "Gridley" returned to San Diego in June 1989. On 17 October of that year, the ship's visit to Naval Station, Treasure Island, California, was interrupted by the 6.9 Loma Prieta earthquake that struck the San Francisco Bay area. "Gridley"s crew provided assistance to victims
1989 Loma Prieta earthquake is the most studied fault on Earth. Andrew Lawson, a geologist from the University of California, Berkeley, had named the fault after the San Andreas Lake (prior to the occurrence of the 1906 San Francisco earthquake) and later led an investigation into that event. The San Andreas Fault ruptured for a length of during the 1906 shock, both to the north of San Francisco and to the south in the Santa Cruz Mountains region. Several long term forecasts for a large shock along the San Andreas Fault in that area had been made public prior to 1989 (the event and