Question: On which day in 1989 did this earthquake occur in which the fireboat "Phoenix" was instrumental in saving the Marina District buildings from further destruction?
Sentence (from "1989 Loma Prieta earthquake"): The Loma Prieta segment of the San Andreas Fault System had been relatively inactive since the 1906 San Francisco earthquake (to the degree that it was designated a seismic gap) until two moderate foreshocks occurred in June 1988 and again in August 1989.
Relevant evidence: No