San Francisco’s Fire Chief will speak at an emergency response drill at Fisherman’s Wharf today from 8:30 a.m. to 11 a.m. Held at San Francisco’s Aquatic Park at Hyde and Jefferson streets, the event marks the 20th anniversary of the Loma Prieta earthquake. Board of Supervisors President David Chiu will also speak at the tribute. More information is available at www.visitfishermanswharf.com.