San Diego County residents heard mysterious booms and felt some rattling Tuesday morning, 10News reported. Residents from all over, including Ramona, called police and 10News to report the loud noises, which some speculated was sonic booms or an earthquake. But no measurable seismic activity was recorded in San Diego County Tuesday morning, according to the U.S. Geological Survey, and Navy and Marine Corps Air Station Miramar officials had no reports of a sonic boom occurring Tuesday. However, Marines at Camp Pendleton were conducting mortar training Tuesday morning. No damage or injuries were reported.